diff --git a/CHANGELOG.md b/CHANGELOG.md
index fc0cb04..b542f55 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -15,6 +15,11 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 
 ### Fixed
 
+- `Invoke-NovaTest`, `Test-NovaBuild`, and `% nova test` now resolve and import a supported installed `Pester` version from `5.7.1` through `5.10.0` instead of using an unsupported `Pester 6.x` installation automatically.
+    - Nova test workflows now fail early with a clear dependency error when only unsupported `Pester 6.x` versions are available.
+- Nova test workflows now reuse an already loaded supported `Pester 5.x` version in the current PowerShell session before selecting a different installed version.
+    - Repository CI no longer trips the `Pester` assembly loader by importing a gallery-installed `NovaModuleTools` module, building the local module, and then switching to another supported `Pester` version in the same session.
+
 ### Security
 
 ## [3.3.0] - 2026-06-16
diff --git a/README.md b/README.md
index ecfbf39..a821b94 100644
--- a/README.md
+++ b/README.md
@@ -4,7 +4,7 @@
 ![WorkFlow Status][WorkFlowStatus]
 [![Keep a Changelog][changelog-badge]][changelog]
 
-NovaModuleTools is an enterprise-focused build tool for Agentic Copilot PowerShell module development, repository automation, and maintainable Nova workflows.
+NovaModuleTools is an enterprise-focused build tool for PowerShell module development, repository automation, and maintainable Nova workflows.
 
 This README is the single developer-documentation entry point for the repository.
 
@@ -298,8 +298,9 @@ Notes:
 - if `project.json` sets `Pester.CodeCoverage.CoveragePercentTarget`, `Invoke-NovaTest` fails when the measured coverage percentage is lower than that configured target
 - this repository currently enables coverage with a `99` percent target; the template and packaged example
   `project.json` files ship the same JaCoCo configuration shape with `Enabled=false` and a `90` percent opt-in target
-- make sure `Pester 5.7.1` is available before running `Invoke-NovaTest` or `Test-NovaBuild`
-- the published `NovaModuleTools` manifest also declares `Pester 5.7.1`, so installed end-user workflows can still resolve that dependency automatically
+- make sure a supported `Pester` version from `5.7.1` through `5.10.0` is available before running `Invoke-NovaTest` or `Test-NovaBuild`
+- Nova resolves and imports a compatible installed `Pester 5.x` version for the managed test workflow and does not run tests with `Pester 6.x`
+- the published `NovaModuleTools` manifest declares `Pester` with `ModuleVersion = 5.7.1` and `MaximumVersion = 5.10.0`, so installed end-user workflows can still resolve that supported dependency range automatically
 
 ### Create a package artifact
 
@@ -640,7 +641,7 @@ Responsibilities currently covered by the release pipeline include:
 - publishing to PowerShell Gallery
 - preparing the next prerelease version on `develop`
 
-The workflow now uses `KeepAChangelog` for changelog release moves, creates annotated git tags named directly from the release version, and bootstraps the local PSResourceGet repository store before calling `Publish-NovaModule`. The shared CI installer also installs `Pester 5.7.1` explicitly before it installs prerelease gallery modules so test workflows do not rely on transitive manifest dependency resolution.
+The workflow now uses `KeepAChangelog` for changelog release moves, creates annotated git tags named directly from the release version, and bootstraps the local PSResourceGet repository store before calling `Publish-NovaModule`. The shared CI installer also installs `Pester 5.7.1` explicitly before it installs prerelease gallery modules so test workflows stay on Nova's supported `Pester 5.x` range and do not rely on transitive manifest dependency resolution.
 
 ### Where NovaModuleTools cmdlets fit
 
diff --git a/RELEASE_NOTE.md b/RELEASE_NOTE.md
index 5b2aa48..676fd3f 100644
--- a/RELEASE_NOTE.md
+++ b/RELEASE_NOTE.md
@@ -14,6 +14,8 @@ This file summarizes the release notes for NovaModuleTools. **UNRELEASED** chang
 
 ### Fixed
 
+- `Invoke-NovaTest`, `Test-NovaBuild`, and `% nova test` now stay on Nova's supported `Pester 5.x` range and stop with a clear error instead of trying to run with an installed `Pester 6.x` version.
+
 ### Security
 
 ## [3.3.0] - 2026-06-16
diff --git a/docs/NovaModuleTools/en-US/Invoke-NovaTest.md b/docs/NovaModuleTools/en-US/Invoke-NovaTest.md
index 9c496e5..1a96d2e 100644
--- a/docs/NovaModuleTools/en-US/Invoke-NovaTest.md
+++ b/docs/NovaModuleTools/en-US/Invoke-NovaTest.md
@@ -32,6 +32,8 @@ PS> Invoke-NovaTest [[-TagFilter] <string[]>] [[-ExcludeTagFilter] <string[]>]
 
 `Invoke-NovaTest` reads the Pester configuration from `project.json`, discovers the repository unit-test files, and runs the managed Nova test workflow without rebuilding the project first.
 
+Nova resolves a supported installed `Pester` version from `5.7.1` through `5.10.0` for the managed test workflow and stops with a clear dependency error when only unsupported `Pester 6.x` versions are available.
+
 The unit-test workflow writes NUnit XML to `artifacts/UnitTestResults.xml`.
 
 When `Pester.CodeCoverage.Enabled` is `true`, Nova also writes JaCoCo coverage to `artifacts/coverage.xml` and fails the run when the measured percentage is lower than `Pester.CodeCoverage.CoveragePercentTarget`.
diff --git a/docs/NovaModuleTools/en-US/Test-NovaBuild.md b/docs/NovaModuleTools/en-US/Test-NovaBuild.md
index 338c8ce..d1988d1 100644
--- a/docs/NovaModuleTools/en-US/Test-NovaBuild.md
+++ b/docs/NovaModuleTools/en-US/Test-NovaBuild.md
@@ -31,11 +31,13 @@ PS> Test-NovaBuild [[-TagFilter] <string[]>] [[-ExcludeTagFilter] <string[]>]
 
 `Test-NovaBuild` reads the Pester configuration from `project.json`, discovers the build-validation integration tests for the current project, and runs the managed Nova test workflow against the built-module validation surface.
 
+Nova resolves a supported installed `Pester` version from `5.7.1` through `5.10.0` for the managed test workflow and stops with a clear dependency error when only unsupported `Pester 6.x` versions are available.
+
 This build-validation flow writes NUnit XML to `artifacts/TestResults.xml`.
 
 Unlike `Invoke-NovaTest`, this command does not enforce source-coverage targets. Use `Invoke-NovaTest` for the unit-test and code-coverage workflow, and use `Test-NovaBuild` when you need build-validation integration coverage that reflects the built module path.
 
-If the current project does not contain any `*.Integration.Tests.ps1` files, `Test-NovaBuild` stops with a Nova-native error that explains the expected naming and reminds you to use `Invoke-NovaTest` for unit tests.
+If the current project does not contain any `*.Integration.Tests.ps1` files, `Test-NovaBuild` writes an actionable warning that explains the expected naming and reminds you to use `Invoke-NovaTest` for unit tests.
 
 `-OverrideWarning` lets the nested build-validation flow continue even if the `src/public` layout guard reports zero or multiple top-level functions in a public file.
 
@@ -271,5 +273,5 @@ Returns the Pester result object from the managed build-validation run.
 
 ## RELATED LINKS
 
-[Invoke-NovaTest](Invoke-NovaTest.md)
-[Invoke-NovaBuild](Invoke-NovaBuild.md)
+- [Invoke-NovaTest](./Invoke-NovaTest.md)
+- [Invoke-NovaBuild](./Invoke-NovaBuild.md)
diff --git a/project.json b/project.json
index e754abc..9e9959a 100644
--- a/project.json
+++ b/project.json
@@ -1,7 +1,7 @@
 {
   "ProjectName": "NovaModuleTools",
-  "Description": "NovaModuleTools is an enterprise-focused build tool for Agentic Copilot PowerShell module development, with a strong emphasis on structure, maintainability, and automated CI/CD pipelines.",
-  "Version": "3.3.0",
+  "Description": "NovaModuleTools is an enterprise-focused build tool for PowerShell module development, with a strong emphasis on structure, maintainability, and build for automated CI/CD pipelines.",
+  "Version": "3.3.1-preview",
   "Preamble": [
     "Set-StrictMode -Version Latest",
     "$ErrorActionPreference = 'Stop'"
@@ -14,7 +14,8 @@
     "RequiredModules": [
       {
         "ModuleName": "Pester",
-        "ModuleVersion": "5.7.1"
+        "ModuleVersion": "5.7.1",
+        "MaximumVersion": "5.10.0"
       },
       {
         "ModuleName": "Microsoft.PowerShell.PlatyPS",
diff --git a/scripts/build/ci/Install-CiPowerShellModules.ps1 b/scripts/build/ci/Install-CiPowerShellModules.ps1
index e3bf041..6f96c8c 100644
--- a/scripts/build/ci/Install-CiPowerShellModules.ps1
+++ b/scripts/build/ci/Install-CiPowerShellModules.ps1
@@ -16,6 +16,7 @@ function Get-CiModuleInstallOption {
     if ($Name -eq 'Pester') {
         return [pscustomobject]@{
             RequiredVersion = '5.7.1'
+            MaximumVersion = '5.10.0'
             AllowPrerelease = $false
         }
     }
diff --git a/scripts/build/ci/Invoke-NovaModuleToolsCI.ps1 b/scripts/build/ci/Invoke-NovaModuleToolsCI.ps1
index 81b38cd..66e3cc3 100644
--- a/scripts/build/ci/Invoke-NovaModuleToolsCI.ps1
+++ b/scripts/build/ci/Invoke-NovaModuleToolsCI.ps1
@@ -16,29 +16,58 @@ function Copy-NovaModuleToolsArtifactIfPresent {
     }
 }
 
+function ConvertTo-NovaSingleQuotedPowerShellLiteral {
+    param(
+        [Parameter(Mandatory)][string]$Value
+    )
+
+    return "'$($Value.Replace("'", "''") )'"
+}
+
+function Get-NovaModuleToolsValidationCommand {
+    param(
+        [Parameter(Mandatory)][string]$BuiltModulePath,
+        [Parameter(Mandatory)][string]$CommandName,
+        [string[]]$ExcludeTag = @()
+    )
+
+    $commandLine = $CommandName
+    if (@($ExcludeTag).Count -gt 0) {
+        $excludeTagLiteral = @($ExcludeTag | ForEach-Object {ConvertTo-NovaSingleQuotedPowerShellLiteral -Value ([string]$_)}) -join ', '
+        $commandLine += " -ExcludeTagFilter @($excludeTagLiteral)"
+    }
+
+    return "Import-Module $( ConvertTo-NovaSingleQuotedPowerShellLiteral -Value $BuiltModulePath ) -Force -ErrorAction Stop; $commandLine"
+}
+
+function Invoke-NovaModuleToolsFreshValidationCommand {
+    param(
+        [Parameter(Mandatory)][string]$Command
+    )
+
+    & pwsh -NoLogo -NoProfile -Command $Command
+    if ($LASTEXITCODE -ne 0) {
+        throw "Validation command failed: $Command"
+    }
+}
+
 $repoRoot = (Resolve-Path -LiteralPath (Join-Path $PSScriptRoot '..' '..' '..')).Path
 Set-Location $repoRoot
 New-Item -ItemType Directory -Path $OutputDirectory -Force | Out-Null
 
 Import-Module NovaModuleTools -ErrorAction Stop
 
-Invoke-NovaBuild
-
-$projectInfo = Get-NovaProjectInfo
-$builtModulePath = $projectInfo.OutputModuleDir
-Remove-Module $projectInfo.ProjectName -ErrorAction SilentlyContinue
-Import-Module $builtModulePath -Force
 $projectInfo = Get-NovaProjectInfo
+Invoke-NovaBuild
+$builtModulePath = Join-Path $projectInfo.OutputModuleDir "$( $projectInfo.ProjectName ).psd1"
 
 $novaModuleToolsTestFailed = $false
 try {
-    if (@($ExcludeTag).Count -gt 0) {
-        Invoke-NovaTest -ExcludeTagFilter $ExcludeTag
-        Test-NovaBuild -ExcludeTagFilter $ExcludeTag
-    } else {
-        Invoke-NovaTest
-        Test-NovaBuild
-    }
+    $unitTestCommand = Get-NovaModuleToolsValidationCommand -BuiltModulePath $builtModulePath -CommandName 'Invoke-NovaTest' -ExcludeTag $ExcludeTag
+    Invoke-NovaModuleToolsFreshValidationCommand -Command $unitTestCommand
+
+    $buildValidationCommand = Get-NovaModuleToolsValidationCommand -BuiltModulePath $builtModulePath -CommandName 'Test-NovaBuild' -ExcludeTag $ExcludeTag
+    Invoke-NovaModuleToolsFreshValidationCommand -Command $buildValidationCommand
 } catch {
     $novaModuleToolsTestFailed = $true
     Write-Warning "Nova test workflow failed: $( $_.Exception.Message )"
diff --git a/src/private/quality/GetNovaTestWorkflowContext.ps1 b/src/private/quality/GetNovaTestWorkflowContext.ps1
index 5741ca2..65f1d8f 100644
--- a/src/private/quality/GetNovaTestWorkflowContext.ps1
+++ b/src/private/quality/GetNovaTestWorkflowContext.ps1
@@ -12,14 +12,192 @@ function Get-NovaTestWorkflowOperation {
 }
 
 function Assert-NovaPesterAvailable {
+    [CmdletBinding()]
+    param(
+        [AllowNull()][pscustomobject]$ProjectInfo
+    )
+
+    $moduleSpecification = Get-NovaSupportedPesterModuleSpecification -ProjectInfo $ProjectInfo
+    Import-NovaSupportedPesterModule -ModuleSpecification $moduleSpecification
+    return $moduleSpecification
+}
+
+function Get-NovaSupportedPesterModuleSpecification {
+    [CmdletBinding()]
+    param(
+        [AllowNull()][pscustomobject]$ProjectInfo
+    )
+
+    $moduleRequirement = Get-NovaPesterModuleRequirement -ProjectInfo $ProjectInfo
+    $availableModule = @(Get-LoadedNovaPesterModule -ModuleRequirement $moduleRequirement)
+    if ($availableModule.Count -eq 0) {
+        $availableModule = @(Get-AvailableNovaPesterModule -ModuleRequirement $moduleRequirement)
+    }
+
+    if ($availableModule.Count -eq 0) {
+        Stop-NovaOperation -Message (Get-NovaPesterDependencyMessage -ModuleRequirement $moduleRequirement) -ErrorId 'Nova.Dependency.PesterDependencyMissing' -Category ResourceUnavailable -TargetObject 'Pester'
+    }
+
+    $selectedVersion = [version]$availableModule[0].Version
+    return [pscustomobject]@{
+        Name = 'Pester'
+        MinimumVersion = $moduleRequirement.MinimumVersion
+        MaximumVersion = $moduleRequirement.MaximumVersion
+        SelectedVersion = $selectedVersion
+        FullyQualifiedName = @{
+            ModuleName = 'Pester'
+            RequiredVersion = [string]$selectedVersion
+        }
+    }
+}
+
+function Get-NovaSupportedPesterRange {
     [CmdletBinding()]
     param()
 
-    if (-not (Get-Module -Name Pester -ListAvailable)) {
-        Stop-NovaOperation -Message 'The module Pester must be installed to run Nova tests. Install Pester 5.7.1 and try again.' -ErrorId 'Nova.Dependency.PesterDependencyMissing' -Category ResourceUnavailable -TargetObject 'Pester'
+    return [pscustomobject]@{
+        Name = 'Pester'
+        MinimumVersion = [version]'5.7.1'
+        MaximumVersion = [version]'5.10.0'
     }
 }
 
+function Get-NovaPesterModuleRequirement {
+    [CmdletBinding()]
+    param(
+        [AllowNull()][pscustomobject]$ProjectInfo
+    )
+
+    $supportedRequirement = Get-NovaSupportedPesterRange
+    $manifestSettings = Get-NovaPesterSettingValue -InputObject $ProjectInfo -Name 'Manifest'
+    $requiredModules = @(Get-NovaPesterSettingValue -InputObject $manifestSettings -Name 'RequiredModules')
+    $pesterModule = $requiredModules |
+            Where-Object {(Get-NovaPesterSettingValue -InputObject $_ -Name 'ModuleName') -eq 'Pester'} |
+            Select-Object -First 1
+
+    if ($null -ne $pesterModule) {
+        $manifestRequirement = [pscustomobject]@{
+            Name = 'Pester'
+            MinimumVersion = [version](Get-NovaPesterVersionText -InputObject $pesterModule -Name 'ModuleVersion' -DefaultValue '5.7.1')
+            MaximumVersion = [version](Get-NovaPesterVersionText -InputObject $pesterModule -Name 'MaximumVersion' -DefaultValue '5.10.0')
+        }
+        Assert-NovaPesterModuleRequirementSupported -ModuleRequirement $manifestRequirement -SupportedRequirement $supportedRequirement
+    }
+
+    return $supportedRequirement
+}
+
+function Assert-NovaPesterModuleRequirementSupported {
+    [CmdletBinding()]
+    param(
+        [Parameter(Mandatory)][pscustomobject]$ModuleRequirement,
+        [Parameter(Mandatory)][pscustomobject]$SupportedRequirement
+    )
+
+    if ($ModuleRequirement.MinimumVersion -eq $SupportedRequirement.MinimumVersion -and $ModuleRequirement.MaximumVersion -eq $SupportedRequirement.MaximumVersion) {
+        return
+    }
+
+    $supportedVersionText = Get-NovaPesterVersionRangeText -ModuleRequirement $SupportedRequirement
+    $declaredVersionText = Get-NovaPesterVersionRangeText -ModuleRequirement $ModuleRequirement
+    Stop-NovaOperation -Message "Nova tests support Pester only from $supportedVersionText. project.json declares Pester from $declaredVersionText. Update project.json to match Nova's supported range and try again." -ErrorId 'Nova.Dependency.UnsupportedPesterVersionRequirement' -Category InvalidData -TargetObject 'project.json'
+}
+
+function Get-NovaPesterVersionText {
+    [CmdletBinding()]
+    param(
+        [AllowNull()][object]$InputObject,
+        [Parameter(Mandatory)][string]$Name,
+        [Parameter(Mandatory)][string]$DefaultValue
+    )
+
+    $value = [string](Get-NovaPesterSettingValue -InputObject $InputObject -Name $Name)
+    if ( [string]::IsNullOrWhiteSpace($value)) {
+        return $DefaultValue
+    }
+
+    return $value
+}
+
+function Get-NovaPesterVersionRangeText {
+    [CmdletBinding()]
+    param(
+        [Parameter(Mandatory)][pscustomobject]$ModuleRequirement
+    )
+
+    return "$( $ModuleRequirement.MinimumVersion ) through $( $ModuleRequirement.MaximumVersion )"
+}
+
+function Get-AvailableNovaPesterModule {
+    [CmdletBinding()]
+    param(
+        [Parameter(Mandatory)][pscustomobject]$ModuleRequirement
+    )
+
+    return @(
+    Get-Module -Name Pester -ListAvailable |
+            Where-Object {Test-NovaPesterModuleVersionSupported -Version $_.Version -ModuleRequirement $ModuleRequirement} |
+            Sort-Object Version -Descending
+    )
+}
+
+function Get-LoadedNovaPesterModule {
+    [CmdletBinding()]
+    param(
+        [Parameter(Mandatory)][pscustomobject]$ModuleRequirement
+    )
+
+    return @(
+    Get-Module -Name Pester |
+            Where-Object {Test-NovaPesterModuleVersionSupported -Version $_.Version -ModuleRequirement $ModuleRequirement} |
+            Sort-Object Version -Descending
+    )
+}
+
+function Test-NovaPesterModuleVersionSupported {
+    [CmdletBinding()]
+    param(
+        [AllowNull()][object]$Version,
+        [Parameter(Mandatory)][pscustomobject]$ModuleRequirement
+    )
+
+    if ($null -eq $Version) {
+        return $false
+    }
+
+    $resolvedVersion = [version]$Version
+    return $resolvedVersion -ge $ModuleRequirement.MinimumVersion -and $resolvedVersion -le $ModuleRequirement.MaximumVersion
+}
+
+function Get-NovaPesterDependencyMessage {
+    [CmdletBinding()]
+    param(
+        [Parameter(Mandatory)][pscustomobject]$ModuleRequirement
+    )
+
+    $supportedVersionText = Get-NovaPesterVersionRangeText -ModuleRequirement $ModuleRequirement
+    $installedVersion = @(
+    Get-Module -Name Pester -ListAvailable |
+            Sort-Object Version -Descending |
+            ForEach-Object {[string]$_.Version} |
+            Select-Object -Unique
+    )
+    if ($installedVersion.Count -eq 0) {
+        return "The module Pester must be installed to run Nova tests. Install a supported Pester version from $supportedVersionText and try again."
+    }
+
+    return "Nova tests require Pester from $supportedVersionText. Installed versions: $( $installedVersion -join ', ' ). Install a supported Pester 5.x version and try again."
+}
+
+function Import-NovaSupportedPesterModule {
+    [CmdletBinding()]
+    param(
+        [Parameter(Mandatory)][pscustomobject]$ModuleSpecification
+    )
+
+    Import-Module -FullyQualifiedName $ModuleSpecification.FullyQualifiedName -Force -ErrorAction Stop | Out-Null
+}
+
 function Get-NovaTestWorkflowContext {
     [CmdletBinding()]
     param(
@@ -27,11 +205,12 @@ function Get-NovaTestWorkflowContext {
         [Parameter(Mandatory)][hashtable]$BoundParameters
     )
 
-    Test-ProjectSchema | Out-Null
-    Assert-NovaPesterAvailable
     $projectInfo = Get-NovaProjectInfo
+    Test-ProjectSchema | Out-Null
+    $pesterModuleSpecification = Assert-NovaPesterAvailable -ProjectInfo $projectInfo
     $workflowProfile = Get-NovaTestWorkflowProfile -TestOption $TestOption
     $pesterConfig = New-PesterConfiguration -Hashtable $projectInfo.Pester
+    Add-Member -InputObject $pesterConfig -MemberType NoteProperty -Name PesterModuleSpecification -Value $pesterModuleSpecification -Force
     $coverageConfiguration = Get-NovaPesterCoverageConfigurationState -ProjectInfo $projectInfo -CoverageEnabled:$workflowProfile.CoverageEnabled
     $pesterConfig.CodeCoverage.Enabled = $coverageConfiguration.Enabled
     $pesterConfig.CodeCoverage.Path = $coverageConfiguration.Path
@@ -62,6 +241,7 @@ function Get-NovaTestWorkflowContext {
         CommandName = $workflowProfile.CommandName
         OverrideWarningRequested = $BoundParameters.ContainsKey('OverrideWarning') -and [bool]$BoundParameters.OverrideWarning
         ProjectInfo = $projectInfo
+        PesterModuleSpecification = $pesterModuleSpecification
         PesterSettings = Get-NovaTestWorkflowPesterConfiguration -ProjectPesterSettings $projectInfo.Pester -CoverageEnabled:$workflowProfile.CoverageEnabled
         PesterConfig = $pesterConfig
         TestResultPath = $testResultPath
diff --git a/src/private/quality/InvokeNovaTestWorkflow.ps1 b/src/private/quality/InvokeNovaTestWorkflow.ps1
index 95be1bb..dd171fb 100644
--- a/src/private/quality/InvokeNovaTestWorkflow.ps1
+++ b/src/private/quality/InvokeNovaTestWorkflow.ps1
@@ -153,7 +153,8 @@ function Invoke-NovaPesterWithSuppressedProgress {
         $heartbeatMilliseconds = 2000
     }
 
-    $execution = Get-NovaPesterExecution -Configuration $Configuration
+    $moduleSpecification = Get-NovaPropertyValue -InputObject $Configuration -Name 'PesterModuleSpecification'
+    $execution = Get-NovaPesterExecution -Configuration $Configuration -ModuleSpecification $moduleSpecification
     try {
         Write-NovaTestWorkflowPesterProgress -Execution $execution -ProgressContext $ProgressContext
         while (-not (Wait-NovaPesterExecution -Execution $execution -TimeoutMilliseconds $HeartbeatMilliseconds)) {
@@ -323,13 +324,19 @@ function Write-NovaPesterHostInformationMessage {
 function Get-NovaPesterExecution {
     [CmdletBinding()]
     param(
-        [Parameter(Mandatory)][object]$Configuration
+        [Parameter(Mandatory)][object]$Configuration,
+        [AllowNull()][object]$ModuleSpecification
     )
 
     $powershell = [powershell]::Create()
     $command = @'
-param($Configuration)
-Import-Module Pester -ErrorAction Stop
+param($Configuration, $ModuleSpecification)
+if ($null -ne $ModuleSpecification) {
+    Import-Module -FullyQualifiedName $ModuleSpecification -Force -ErrorAction Stop
+}
+else {
+    Import-Module Pester -ErrorAction Stop
+}
 $previousProgressPreference = $global:ProgressPreference
 $global:ProgressPreference = 'SilentlyContinue'
 try {
@@ -338,7 +345,12 @@ try {
     $global:ProgressPreference = $previousProgressPreference
 }
 '@
-    $null = $powershell.AddScript($command).AddArgument($Configuration)
+    $moduleImportSpecification = $null
+    if ($null -ne $ModuleSpecification) {
+        $moduleImportSpecification = Get-NovaPropertyValue -InputObject $ModuleSpecification -Name 'FullyQualifiedName'
+    }
+
+    $null = $powershell.AddScript($command).AddArgument($Configuration).AddArgument($moduleImportSpecification)
 
     return [pscustomobject]@{
         PowerShell = $powershell
diff --git a/tests/Invoke-NovaModuleToolsCI.Tests.ps1 b/tests/Invoke-NovaModuleToolsCI.Tests.ps1
index 848f5fb..a2b4c4a 100644
--- a/tests/Invoke-NovaModuleToolsCI.Tests.ps1
+++ b/tests/Invoke-NovaModuleToolsCI.Tests.ps1
@@ -37,7 +37,7 @@ Describe 'Invoke-NovaModuleToolsCI' {
         $projectRoot = Join-Path $TestDrive 'project'
         $outputDirectory = Join-Path $TestDrive 'artifacts-out'
         $callLogPath = Join-Path $TestDrive 'call-log.txt'
-        $excludeTagLogPath = Join-Path $TestDrive 'exclude-tags.txt'
+        $commandLogPath = Join-Path $TestDrive 'commands.txt'
         $unitResultPath = Join-Path $projectRoot 'artifacts/UnitTestResults.xml'
         $integrationResultPath = Join-Path $projectRoot 'artifacts/TestResults.xml'
 
@@ -64,24 +64,24 @@ function Get-NovaProjectInfo {
     }
 }
 
-function Remove-Module {
+function pwsh {
     [CmdletBinding()]
-    param([string]`$Name)
-}
-
-function Invoke-NovaTest {
-    [CmdletBinding()]
-    param([string[]]`$ExcludeTagFilter)
+    param(
+        [switch]`$NoLogo,
+        [switch]`$NoProfile,
+        [string]`$Command
+    )
 
-    Add-Content -LiteralPath '$callLogPath' -Value 'Invoke-NovaTest'
-    Set-Content -LiteralPath '$excludeTagLogPath' -Value (`$ExcludeTagFilter -join ',') -Encoding utf8
-}
+    Add-Content -LiteralPath '$commandLogPath' -Value `$Command
+    if (`$Command -match 'Invoke-NovaTest') {
+        Add-Content -LiteralPath '$callLogPath' -Value 'Invoke-NovaTest'
+    }
 
-function Test-NovaBuild {
-    [CmdletBinding()]
-    param([string[]]`$ExcludeTagFilter)
+    if (`$Command -match 'Test-NovaBuild') {
+        Add-Content -LiteralPath '$callLogPath' -Value 'Test-NovaBuild'
+    }
 
-    Add-Content -LiteralPath '$callLogPath' -Value 'Test-NovaBuild'
+    `$global:LASTEXITCODE = 0
 }
 
 & '$script:novaModuleToolsCiScriptPath' -OutputDirectory '$outputDirectory' -ExcludeTag 'slow','integration'
@@ -90,7 +90,10 @@ function Test-NovaBuild {
 
         $result.ExitCode | Should -Be 0 -Because ($result.Output -join [Environment]::NewLine)
         (Get-Content -LiteralPath $callLogPath) | Should -Be @('Invoke-NovaTest', 'Test-NovaBuild')
-        (Get-Content -LiteralPath $excludeTagLogPath -Raw).Trim() | Should -Be 'slow,integration'
+        $commands = Get-Content -LiteralPath $commandLogPath
+        $commands | Should -HaveCount 2
+        $commands[0] | Should -Match "Import-Module '.*/dist/NovaModuleTools/NovaModuleTools\.psd1' -Force -ErrorAction Stop; Invoke-NovaTest -ExcludeTagFilter @\('slow', 'integration'\)"
+        $commands[1] | Should -Match "Import-Module '.*/dist/NovaModuleTools/NovaModuleTools\.psd1' -Force -ErrorAction Stop; Test-NovaBuild -ExcludeTagFilter @\('slow', 'integration'\)"
         (Get-Content -LiteralPath (Join-Path $outputDirectory 'novamoduletools-unit-nunit.xml') -Raw).Trim() | Should -Be '<unit-test-results />'
         (Get-Content -LiteralPath (Join-Path $outputDirectory 'novamoduletools-integration-nunit.xml') -Raw).Trim() | Should -Be '<integration-test-results />'
     }
@@ -122,16 +125,21 @@ function Get-NovaProjectInfo {
     }
 }
 
-function Remove-Module {
+function pwsh {
     [CmdletBinding()]
-    param([string]`$Name)
-}
+    param(
+        [switch]`$NoLogo,
+        [switch]`$NoProfile,
+        [string]`$Command
+    )
 
-function Invoke-NovaTest {
-    throw 'boom'
-}
+    if (`$Command -match 'Invoke-NovaTest') {
+        `$global:LASTEXITCODE = 1
+        return
+    }
 
-function Test-NovaBuild {}
+    `$global:LASTEXITCODE = 0
+}
 
 & '$script:novaModuleToolsCiScriptPath' -OutputDirectory '$outputDirectory'
 "@
@@ -139,7 +147,7 @@ function Test-NovaBuild {}
         $outputText = $result.Output -join [Environment]::NewLine
 
         $result.ExitCode | Should -Be 1
-        $outputText | Should -Match 'Nova test workflow failed: boom'
+        $outputText | Should -Match 'Nova test workflow failed: Validation command failed: .*Invoke-NovaTest'
         (Get-Content -LiteralPath (Join-Path $outputDirectory 'novamoduletools-unit-nunit.xml') -Raw).Trim() | Should -Be '<failed-unit-test-results />'
         Test-Path -LiteralPath (Join-Path $outputDirectory 'novamoduletools-integration-nunit.xml') | Should -BeFalse
     }
diff --git a/tests/TestHelpers/PublicCommandIntegration.ps1 b/tests/TestHelpers/PublicCommandIntegration.ps1
index e1587ec..f9b56b1 100644
--- a/tests/TestHelpers/PublicCommandIntegration.ps1
+++ b/tests/TestHelpers/PublicCommandIntegration.ps1
@@ -46,3 +46,71 @@ function Invoke-NovaPublicCommandIntegrationInProjectRoot {
 
     return Invoke-NovaPublicCommandIntegrationInLocation -Path $ProjectRoot -ScriptBlock $ScriptBlock
 }
+
+function Get-NovaPublicCommandIntegrationOutputText {
+    [CmdletBinding()]
+    param(
+        [Parameter(Mandatory)][object[]]$Output,
+        [switch]$NormalizeWhitespace
+    )
+
+    $text = @($Output) -join [Environment]::NewLine
+    $text = [regex]::Replace($text, '\x1B\[[0-?]*[ -/]*[@-~]', '')
+    if ($NormalizeWhitespace) {
+        $text = [regex]::Replace($text, '\s+', ' ')
+    }
+
+    return $text.Trim()
+}
+
+function Invoke-NovaPublicCommandIntegrationInIsolatedSession {
+    [CmdletBinding()]
+    param(
+        [Parameter(Mandatory)][string]$ProjectRoot,
+        [string]$Path = $ProjectRoot,
+        [Parameter(Mandatory)][scriptblock]$ScriptBlock
+    )
+
+    $runnerPath = Join-Path $TestDrive 'Run-NovaPublicCommandIntegration.ps1'
+    $moduleManifestPath = Join-Path $ProjectRoot 'dist/NovaModuleTools/NovaModuleTools.psd1'
+    $escapedManifestPath = $moduleManifestPath.Replace("'", "''")
+    $escapedLocationPath = $Path.Replace("'", "''")
+    $runnerContent = @"
+function New-NovaPublicCommandIntegrationPesterModule {
+    param(
+        [Parameter(Mandatory)][string]`$BasePath,
+        [Parameter(Mandatory)][string]`$Version
+    )
+
+    `$moduleRoot = Join-Path `$BasePath "Pester/`$Version"
+    `$null = New-Item -ItemType Directory -Path `$moduleRoot -Force
+    Set-Content -LiteralPath (Join-Path `$moduleRoot 'Pester.psm1') -Value '' -Encoding utf8
+    `$manifestContent = @(
+        '@{'
+        "    RootModule = 'Pester.psm1'"
+    "    ModuleVersion = '`$Version'"
+    "    GUID = '`$([guid]::NewGuid().Guid)'"
+        '    FunctionsToExport = @()'
+        '    CmdletsToExport = @()'
+        '    VariablesToExport = @()'
+        '    AliasesToExport = @()'
+        '}'
+    ) -join [Environment]::NewLine
+    Set-Content -LiteralPath (Join-Path `$moduleRoot 'Pester.psd1') -Value `$manifestContent -Encoding utf8
+}
+
+Import-Module '$escapedManifestPath' -Force -ErrorAction Stop
+Set-Location -LiteralPath '$escapedLocationPath'
+& {
+$($ScriptBlock.ToString() )
+}
+"@
+    Set-Content -LiteralPath $runnerPath -Value $runnerContent -Encoding utf8
+
+    $output = & pwsh -NoLogo -NoProfile -File $runnerPath 2>&1
+    return [pscustomobject]@{
+        ExitCode = $LASTEXITCODE
+        Output = @($output)
+    }
+}
+
diff --git a/tests/private/quality/GetNovaTestWorkflowContext.TestSupport.ps1 b/tests/private/quality/GetNovaTestWorkflowContext.TestSupport.ps1
index 3760e10..b2ac60b 100644
--- a/tests/private/quality/GetNovaTestWorkflowContext.TestSupport.ps1
+++ b/tests/private/quality/GetNovaTestWorkflowContext.TestSupport.ps1
@@ -1,7 +1,20 @@
-function Test-ProjectSchema {param($Name) }
-function Stop-NovaOperation {param($Message, $ErrorId, $Category, $TargetObject) throw $Message}
-function Get-NovaProjectInfo {}
-function New-PesterConfiguration {param($Hashtable)}
+function Test-ProjectSchema {
+    param($Name)
+}
+
+function Stop-NovaOperation {
+    param($Message, $ErrorId, $Category, $TargetObject)
+
+    throw $Message
+}
+
+function Get-NovaProjectInfo {
+}
+
+function New-PesterConfiguration {
+    param($Hashtable)
+}
+
 function Get-NovaPesterRunPath {
     param($ProjectInfo, $IncludePattern, $ExcludePattern)
 
@@ -32,12 +45,20 @@ function Initialize-NovaPesterExecutionConfiguration {
         ExecutionOption = $ExecutionOption
     }
 }
-function Get-NovaShouldProcessForwardingParameter {param([switch]$WhatIfEnabled) return @{}}
-function Write-NovaPesterTestResultArtifact {}
-function Write-NovaPesterTestResultReport {}
+function Get-NovaShouldProcessForwardingParameter {
+    param([switch]$WhatIfEnabled)
 
-$script:getPesterConfig = {
-    [pscustomobject]@{
+    return @{}
+}
+
+function Write-NovaPesterTestResultArtifact {
+}
+
+function Write-NovaPesterTestResultReport {
+}
+
+function New-TestPesterConfig {
+    return [pscustomobject]@{
         Run = [pscustomobject]@{Path = $null; PassThru = $false; Exit = $false; Throw = $false}
         Filter = [pscustomobject]@{Tag = @(); ExcludeTag = @()}
         Output = [pscustomobject]@{Verbosity = 'Detailed'; RenderMode = 'Auto'}
@@ -46,14 +67,29 @@ $script:getPesterConfig = {
     }
 }
 
-$script:getProjectInfo = {
+function New-TestProjectInfo {
     param(
         [Parameter(Mandatory)][object]$PesterSettings,
+        [AllowNull()][object[]]$ManifestRequiredModules = $null,
         [string]$ProjectRoot = (Join-Path $TestDrive 'nova-project')
     )
 
-    [pscustomobject]@{
+    $requiredModules = $ManifestRequiredModules
+    if ($null -eq $requiredModules) {
+        $requiredModules = @(
+            [ordered]@{
+                ModuleName = 'Pester'
+                ModuleVersion = '5.7.1'
+                MaximumVersion = '5.10.0'
+            }
+        )
+    }
+
+    return [pscustomobject]@{
         Pester = $PesterSettings
+        Manifest = [ordered]@{
+            RequiredModules = @($requiredModules)
+        }
         BuildRecursiveFolders = $true
         TestsDir = (Join-Path $ProjectRoot 'tests')
         ProjectRoot = $ProjectRoot
diff --git a/tests/private/quality/GetNovaTestWorkflowContext.Tests.ps1 b/tests/private/quality/GetNovaTestWorkflowContext.Tests.ps1
index 4b1998d..61ba5a4 100644
--- a/tests/private/quality/GetNovaTestWorkflowContext.Tests.ps1
+++ b/tests/private/quality/GetNovaTestWorkflowContext.Tests.ps1
@@ -10,15 +10,29 @@ Describe 'Get-NovaTestWorkflowContext' {
         $script:lastRunPathRequest = $null
         $script:lastResultPathRequest = $null
         $script:lastExecutionConfigurationRequest = $null
+        $script:lastImportModuleRequest = $null
 
         Mock Test-ProjectSchema {}
-        Mock Get-Module {[pscustomobject]@{Name = 'Pester'}} -ParameterFilter {$Name -eq 'Pester' -and $ListAvailable}
+        Mock Get-Module {
+            @()
+        } -ParameterFilter {$Name -eq 'Pester' -and -not $ListAvailable}
+        Mock Get-Module {
+            @(
+                [pscustomobject]@{Name = 'Pester'; Version = [version]'5.10.0'}
+            )
+        } -ParameterFilter {$Name -eq 'Pester' -and $ListAvailable}
+        Mock Import-Module {
+            $script:lastImportModuleRequest = [pscustomobject]@{
+                FullyQualifiedName = $PSBoundParameters.FullyQualifiedName
+                Force = $PSBoundParameters.Force
+            }
+        }
         Mock Get-Command {[pscustomobject]@{ScriptBlock = {}}} -ParameterFilter {$CommandType -eq 'Function'}
     }
 
     It 'configures unit-test execution with coverage enabled and integration tests excluded' {
-        $pesterConfig = & $script:getPesterConfig
-        $projectInfo = & $script:getProjectInfo -PesterSettings ([ordered]@{
+        $pesterConfig = New-TestPesterConfig
+        $projectInfo = New-TestProjectInfo -PesterSettings ([ordered]@{
             CodeCoverage = [ordered]@{
                 Enabled = $true
                 CoveragePercentTarget = 99
@@ -33,16 +47,66 @@ Describe 'Get-NovaTestWorkflowContext' {
         $result.BuildRequested | Should -BeFalse
         $result.CommandName | Should -Be 'Invoke-NovaTest'
         $result.PesterConfig.CodeCoverage.CoveragePercentTarget | Should -Be 99
+        $result.PesterConfig.PesterModuleSpecification.SelectedVersion | Should -Be ([version]'5.10.0')
+        $result.PesterModuleSpecification.SelectedVersion | Should -Be ([version]'5.10.0')
         $result.PesterSettings.CodeCoverage.Enabled | Should -BeTrue
         $script:lastRunPathRequest.IncludePattern | Should -Be '*.Tests.ps1'
         $script:lastRunPathRequest.ExcludePattern | Should -Be @('*.Integration.Tests.ps1')
         $script:lastResultPathRequest.FileName | Should -Be 'UnitTestResults.xml'
+        $result.PesterModuleSpecification.FullyQualifiedName.ModuleName | Should -Be 'Pester'
+        $result.PesterModuleSpecification.FullyQualifiedName.RequiredVersion | Should -Be '5.10.0'
         $result.Operation | Should -Be 'Run unit tests and write test results'
     }
 
+    It 'selects the highest supported Pester 5.x version when Pester 6 is also installed' {
+        $pesterConfig = New-TestPesterConfig
+        $projectInfo = New-TestProjectInfo -PesterSettings ([ordered]@{})
+
+        Mock Get-NovaProjectInfo {$projectInfo}
+        Mock New-PesterConfiguration {$pesterConfig}
+        Mock Get-Module {
+            @(
+                [pscustomobject]@{Name = 'Pester'; Version = [version]'6.0.0'}
+                [pscustomobject]@{Name = 'Pester'; Version = [version]'5.10.0'}
+                [pscustomobject]@{Name = 'Pester'; Version = [version]'5.7.1'}
+            )
+        } -ParameterFilter {$Name -eq 'Pester' -and $ListAvailable}
+
+        $result = Get-NovaTestWorkflowContext -TestOption @{TestMode = 'Unit'} -BoundParameters @{}
+
+        $result.PesterModuleSpecification.SelectedVersion | Should -Be ([version]'5.10.0')
+        $result.PesterConfig.PesterModuleSpecification.SelectedVersion | Should -Be ([version]'5.10.0')
+        $result.PesterModuleSpecification.FullyQualifiedName.RequiredVersion | Should -Be '5.10.0'
+    }
+
+    It 'reuses the already loaded supported Pester version instead of switching versions mid-session' {
+        $pesterConfig = New-TestPesterConfig
+        $projectInfo = New-TestProjectInfo -PesterSettings ([ordered]@{})
+
+        Mock Get-NovaProjectInfo {$projectInfo}
+        Mock New-PesterConfiguration {$pesterConfig}
+        Mock Get-Module {
+            @(
+                [pscustomobject]@{Name = 'Pester'; Version = [version]'5.7.1'}
+            )
+        } -ParameterFilter {$Name -eq 'Pester' -and -not $ListAvailable}
+        Mock Get-Module {
+            @(
+                [pscustomobject]@{Name = 'Pester'; Version = [version]'5.8.0'}
+                [pscustomobject]@{Name = 'Pester'; Version = [version]'5.7.1'}
+            )
+        } -ParameterFilter {$Name -eq 'Pester' -and $ListAvailable}
+
+        $result = Get-NovaTestWorkflowContext -TestOption @{TestMode = 'Unit'} -BoundParameters @{}
+
+        $result.PesterModuleSpecification.SelectedVersion | Should -Be ([version]'5.7.1')
+        $result.PesterModuleSpecification.FullyQualifiedName.RequiredVersion | Should -Be '5.7.1'
+        Assert-MockCalled Import-Module -Times 1 -ParameterFilter {$FullyQualifiedName.RequiredVersion -eq '5.7.1' -and $Force}
+    }
+
     It 'configures build-validation execution with coverage disabled and integration-only test discovery' {
-        $pesterConfig = & $script:getPesterConfig
-        $projectInfo = & $script:getProjectInfo -PesterSettings ([ordered]@{
+        $pesterConfig = New-TestPesterConfig
+        $projectInfo = New-TestProjectInfo -PesterSettings ([ordered]@{
             CodeCoverage = [ordered]@{
                 Enabled = $true
                 CoveragePercentTarget = 99
@@ -67,8 +131,8 @@ Describe 'Get-NovaTestWorkflowContext' {
     }
 
     It 'returns a skip state with actionable guidance when build-validation tests are missing' {
-        $pesterConfig = & $script:getPesterConfig
-        $projectInfo = & $script:getProjectInfo -PesterSettings ([ordered]@{})
+        $pesterConfig = New-TestPesterConfig
+        $projectInfo = New-TestProjectInfo -PesterSettings ([ordered]@{})
 
         Mock Get-NovaProjectInfo {$projectInfo}
         Mock New-PesterConfiguration {$pesterConfig}
@@ -96,8 +160,8 @@ Describe 'Get-NovaTestWorkflowContext' {
             Set-Content -LiteralPath $filePath -Value '# test'
         }
 
-        $pesterConfig = & $script:getPesterConfig
-        $projectInfo = & $script:getProjectInfo -ProjectRoot $projectRoot -PesterSettings ([ordered]@{
+        $pesterConfig = New-TestPesterConfig
+        $projectInfo = New-TestProjectInfo -ProjectRoot $projectRoot -PesterSettings ([ordered]@{
             CodeCoverage = [ordered]@{
                 Enabled = $true
                 Path = @(
@@ -123,8 +187,8 @@ Describe 'Get-NovaTestWorkflowContext' {
     }
 
     It 'forwards the guarded Pester configuration override to the execution configuration initializer' {
-        $pesterConfig = & $script:getPesterConfig
-        $projectInfo = & $script:getProjectInfo -PesterSettings ([ordered]@{})
+        $pesterConfig = New-TestPesterConfig
+        $projectInfo = New-TestProjectInfo -PesterSettings ([ordered]@{})
         $containerOverride = [pscustomobject]@{
             Type = 'File'
             Item = (Join-Path $projectInfo.ProjectRoot 'tests/Example.Tests.ps1')
@@ -212,14 +276,172 @@ Describe 'Get-NovaDiscoveredTestPathState' {
 }
 
 Describe 'Assert-NovaPesterAvailable' {
+    BeforeEach {
+        $script:lastImportModuleRequest = $null
+        Mock Get-Module {
+            @()
+        } -ParameterFilter {$Name -eq 'Pester' -and -not $ListAvailable}
+        Mock Import-Module {
+            $script:lastImportModuleRequest = [pscustomobject]@{
+                FullyQualifiedName = $PSBoundParameters.FullyQualifiedName
+                Force = $PSBoundParameters.Force
+            }
+        }
+    }
+
     It 'stops with Nova.Dependency.PesterDependencyMissing when Pester is missing' {
         Mock Get-Module {@()} -ParameterFilter {$Name -eq 'Pester' -and $ListAvailable}
-        {Assert-NovaPesterAvailable} | Should -Throw
+        {Assert-NovaPesterAvailable -ProjectInfo (New-TestProjectInfo -PesterSettings ([ordered]@{}))} | Should -Throw
+    }
+
+    It 'stops when only unsupported Pester 6.x versions are installed' {
+        Mock Get-Module {
+            @(
+                [pscustomobject]@{Name = 'Pester'; Version = [version]'6.0.0'}
+            )
+        } -ParameterFilter {$Name -eq 'Pester' -and $ListAvailable}
+
+        $thrown = $null
+        try {
+            Assert-NovaPesterAvailable -ProjectInfo (New-TestProjectInfo -PesterSettings ([ordered]@{}))
+        } catch {
+            $thrown = $_
+        }
+
+        $thrown | Should -Not -BeNullOrEmpty
+        $thrown | Should -Match '5.7.1 through 5.10.0'
+        $thrown | Should -Match '6.0.0'
+    }
+
+    It 'returns the selected supported Pester specification when Pester is available' {
+        Mock Get-Module {
+            @(
+                [pscustomobject]@{Name = 'Pester'; Version = [version]'5.10.0'}
+            )
+        } -ParameterFilter {$Name -eq 'Pester' -and $ListAvailable}
+
+        $result = Assert-NovaPesterAvailable -ProjectInfo (New-TestProjectInfo -PesterSettings ([ordered]@{}))
+
+        $result.SelectedVersion | Should -Be ([version]'5.10.0')
+        $result.FullyQualifiedName.RequiredVersion | Should -Be '5.10.0'
+    }
+}
+
+Describe 'Get-NovaSupportedPesterModuleSpecification' {
+    It 'reuses the loaded supported Pester version before considering higher installed versions' {
+        $projectInfo = New-TestProjectInfo -PesterSettings ([ordered]@{})
+        Mock Get-Module {
+            @(
+                [pscustomobject]@{Name = 'Pester'; Version = [version]'5.7.1'}
+            )
+        } -ParameterFilter {$Name -eq 'Pester' -and -not $ListAvailable}
+        Mock Get-Module {
+            @(
+                [pscustomobject]@{Name = 'Pester'; Version = [version]'5.10.0'}
+                [pscustomobject]@{Name = 'Pester'; Version = [version]'5.7.1'}
+            )
+        } -ParameterFilter {$Name -eq 'Pester' -and $ListAvailable}
+
+        $result = Get-NovaSupportedPesterModuleSpecification -ProjectInfo $projectInfo
+
+        $result.SelectedVersion | Should -Be ([version]'5.7.1')
+    }
+
+    It 'selects the highest installed version inside Nova''s supported Pester range' {
+        $projectInfo = New-TestProjectInfo -PesterSettings ([ordered]@{})
+        Mock Get-Module {@()} -ParameterFilter {$Name -eq 'Pester' -and -not $ListAvailable}
+        Mock Get-Module {
+            @(
+                [pscustomobject]@{Name = 'Pester'; Version = [version]'5.10.1'}
+                [pscustomobject]@{Name = 'Pester'; Version = [version]'5.8.0'}
+                [pscustomobject]@{Name = 'Pester'; Version = [version]'5.10.0'}
+                [pscustomobject]@{Name = 'Pester'; Version = [version]'5.7.1'}
+                [pscustomobject]@{Name = 'Pester'; Version = [version]'5.7.0'}
+            )
+        } -ParameterFilter {$Name -eq 'Pester' -and $ListAvailable}
+
+        $result = Get-NovaSupportedPesterModuleSpecification -ProjectInfo $projectInfo
+
+        $result.MinimumVersion | Should -Be ([version]'5.7.1')
+        $result.MaximumVersion | Should -Be ([version]'5.10.0')
+        $result.SelectedVersion | Should -Be ([version]'5.10.0')
+    }
+
+    It 'falls back to the default supported Pester range when the manifest does not declare Pester' {
+        $projectInfo = [pscustomobject]@{
+            Pester = [ordered]@{}
+            Manifest = [ordered]@{RequiredModules = @()}
+        }
+        Mock Get-Module {@()} -ParameterFilter {$Name -eq 'Pester' -and -not $ListAvailable}
+        Mock Get-Module {
+            @(
+                [pscustomobject]@{Name = 'Pester'; Version = [version]'5.7.1'}
+            )
+        } -ParameterFilter {$Name -eq 'Pester' -and $ListAvailable}
+
+        $result = Get-NovaSupportedPesterModuleSpecification -ProjectInfo $projectInfo
+
+        $result.MinimumVersion | Should -Be ([version]'5.7.1')
+        $result.MaximumVersion | Should -Be ([version]'5.10.0')
+        $result.SelectedVersion | Should -Be ([version]'5.7.1')
+    }
+
+    It 'stops when project.json declares a wider Pester range than Nova supports' {
+        $projectInfo = New-TestProjectInfo -PesterSettings ([ordered]@{}) -ManifestRequiredModules @(
+            [ordered]@{
+                ModuleName = 'Pester'
+                ModuleVersion = '5.7.1'
+                MaximumVersion = '6.0.0'
+            }
+        )
+
+        $thrown = $null
+        try {
+            $null = Get-NovaSupportedPesterModuleSpecification -ProjectInfo $projectInfo
+        } catch {
+            $thrown = $_
+        }
+
+        $thrown | Should -Not -BeNullOrEmpty
+        $thrown | Should -Match '5.7.1 through 5.10.0'
+        $thrown | Should -Match 'project.json declares Pester from 5.7.1 through 6.0.0'
+    }
+}
+
+Describe 'Get-NovaPesterVersionText' {
+    It 'returns the default value when the requested setting is empty' {
+        $moduleInfo = [pscustomobject]@{
+            ModuleVersion = ''
+        }
+
+        $result = Get-NovaPesterVersionText -InputObject $moduleInfo -Name 'ModuleVersion' -DefaultValue '5.7.1'
+
+        $result | Should -Be '5.7.1'
     }
+}
+
+Describe 'Test-NovaPesterModuleVersionSupported' {
+    It 'accepts only versions inside Nova''s supported Pester range' {
+        $moduleRequirement = Get-NovaPesterModuleRequirement -ProjectInfo (New-TestProjectInfo -PesterSettings ([ordered]@{}))
+        $cases = @(
+            [pscustomobject]@{Version = '5.7.0'; Expected = $false}
+            [pscustomobject]@{Version = '5.7.1'; Expected = $true}
+            [pscustomobject]@{Version = '5.10.0'; Expected = $true}
+            [pscustomobject]@{Version = '5.10.1'; Expected = $false}
+        )
+
+        foreach ($case in $cases) {
+            $actual = Test-NovaPesterModuleVersionSupported -Version ([version]$case.Version) -ModuleRequirement $moduleRequirement
+            $actual | Should -Be $case.Expected -Because $case.Version
+        }
+    }
+
+    It 'returns false when the candidate version is null' {
+        $moduleRequirement = Get-NovaPesterModuleRequirement -ProjectInfo (New-TestProjectInfo -PesterSettings ([ordered]@{}))
+
+        $result = Test-NovaPesterModuleVersionSupported -Version $null -ModuleRequirement $moduleRequirement
 
-    It 'returns silently when Pester is available' {
-        Mock Get-Module {@([pscustomobject]@{Name = 'Pester'})} -ParameterFilter {$Name -eq 'Pester' -and $ListAvailable}
-        {Assert-NovaPesterAvailable} | Should -Not -Throw
+        $result | Should -BeFalse
     }
 }
 
@@ -304,7 +526,7 @@ Describe 'Get-NovaDisabledPesterCoverageConfiguration' {
 
 Describe 'Get-NovaPesterCoverageConfigurationState' {
     It 'returns disabled coverage settings when coverage is disabled for the workflow' {
-        $projectInfo = & $script:getProjectInfo -PesterSettings ([ordered]@{
+        $projectInfo = New-TestProjectInfo -PesterSettings ([ordered]@{
             CodeCoverage = [ordered]@{
                 Enabled = $true
                 CoveragePercentTarget = 99
@@ -324,7 +546,7 @@ Describe 'Get-NovaPesterCoverageConfigurationState' {
         $filePath = Join-Path $projectRoot 'src/public/GetAlpha.ps1'
         New-Item -ItemType Directory -Path (Split-Path -Parent $filePath) -Force | Out-Null
         Set-Content -LiteralPath $filePath -Value '# test'
-        $projectInfo = & $script:getProjectInfo -ProjectRoot $projectRoot -PesterSettings ([ordered]@{
+        $projectInfo = New-TestProjectInfo -ProjectRoot $projectRoot -PesterSettings ([ordered]@{
             CodeCoverage = [ordered]@{
                 Enabled = $true
                 CoveragePercentTarget = 99
diff --git a/tests/private/quality/InvokeNovaTestWorkflow.Tests.ps1 b/tests/private/quality/InvokeNovaTestWorkflow.Tests.ps1
index 8e625f4..cda0718 100644
--- a/tests/private/quality/InvokeNovaTestWorkflow.Tests.ps1
+++ b/tests/private/quality/InvokeNovaTestWorkflow.Tests.ps1
@@ -354,7 +354,16 @@ Describe 'Invoke-NovaPesterWithSuppressedProgress' {
             $script:outputCallCount += 1
         }
 
-        $result = Invoke-NovaPesterWithSuppressedProgress -Configuration ([pscustomobject]@{}) -ProgressContext ([pscustomobject]@{
+        $configuration = [pscustomobject]@{
+            PesterModuleSpecification = [pscustomobject]@{
+                FullyQualifiedName = @{
+                    ModuleName = 'Pester'
+                    RequiredVersion = '5.10.0'
+                }
+            }
+        }
+
+        $result = Invoke-NovaPesterWithSuppressedProgress -Configuration $configuration -ProgressContext ([pscustomobject]@{
             Activity = 'Running Nova test workflow'
             StartPercentComplete = 70
             EndPercentComplete = 94
@@ -362,7 +371,10 @@ Describe 'Invoke-NovaPesterWithSuppressedProgress' {
         })
 
         $result.Result | Should -Be 'Passed'
-        Should -Invoke Get-NovaPesterExecution -Times 1
+        Should -Invoke Get-NovaPesterExecution -Times 1 -ParameterFilter {
+            $ModuleSpecification.FullyQualifiedName.ModuleName -eq 'Pester' -and
+                    $ModuleSpecification.FullyQualifiedName.RequiredVersion -eq '5.10.0'
+        }
         Should -Invoke Wait-NovaPesterExecution -Times 3
         Should -Invoke Write-NovaPesterExecutionOutput -Times 3
         Should -Invoke Receive-NovaPesterExecutionResult -Times 1
@@ -565,7 +577,12 @@ Describe 'Get-NovaPesterExecution' {
     It 'returns an execution object with the expected initial properties' {
         $execution = $null
         try {
-            $execution = Get-NovaPesterExecution -Configuration ([pscustomobject]@{})
+            $execution = Get-NovaPesterExecution -Configuration ([pscustomobject]@{}) -ModuleSpecification ([pscustomobject]@{
+                FullyQualifiedName = @{
+                    ModuleName = 'Pester'
+                    RequiredVersion = '5.10.0'
+                }
+            })
             $execution.PowerShell | Should -Not -BeNullOrEmpty
             $execution.AsyncResult | Should -Not -BeNullOrEmpty
             $execution.CompletedTestCount | Should -Be 0
@@ -573,6 +590,11 @@ Describe 'Get-NovaPesterExecution' {
             $execution.TotalTestCount | Should -BeNullOrEmpty
             $execution.LastProgressStatus | Should -BeNullOrEmpty
             $execution.LastProgressPercentComplete | Should -BeNullOrEmpty
+
+            $commands = $execution.PowerShell.Commands.Commands
+            $commands.Count | Should -Be 1
+            $commands[0].Parameters[1].Value.ModuleName | Should -Be 'Pester'
+            $commands[0].Parameters[1].Value.RequiredVersion | Should -Be '5.10.0'
         } finally {
             if ($null -ne $execution -and $null -ne $execution.PowerShell) {
                 $execution.PowerShell.Dispose()
diff --git a/tests/public/InvokeNovaTest.Integration.Tests.ps1 b/tests/public/InvokeNovaTest.Integration.Tests.ps1
index f260407..07899bc 100644
--- a/tests/public/InvokeNovaTest.Integration.Tests.ps1
+++ b/tests/public/InvokeNovaTest.Integration.Tests.ps1
@@ -6,48 +6,75 @@ BeforeAll {
 
 Describe 'Invoke-NovaTest integration' {
     It 'supports WhatIf from the built module' {
-        {
-            Invoke-NovaPublicCommandIntegrationInProjectRoot -ProjectRoot $script:projectRoot -ScriptBlock {
+        $result = Invoke-NovaPublicCommandIntegrationInIsolatedSession -ProjectRoot $script:projectRoot -ScriptBlock {
+            Invoke-NovaTest -WhatIf
+        }
+
+        $result.ExitCode | Should -Be 0 -Because (Get-NovaPublicCommandIntegrationOutputText -Output $result.Output)
+    }
+
+    It 'fails early when the isolated session cannot resolve a supported Pester 5.x module' {
+        $result = Invoke-NovaPublicCommandIntegrationInIsolatedSession -ProjectRoot $script:projectRoot -ScriptBlock {
+            $temporaryModulePath = Join-Path ([System.IO.Path]::GetTempPath()) ([System.Guid]::NewGuid().Guid)
+            $originalModulePath = $env:PSModulePath
+            try {
+                New-NovaPublicCommandIntegrationPesterModule -BasePath $temporaryModulePath -Version '6.0.0' | Out-Null
+                $env:PSModulePath = $temporaryModulePath
                 Invoke-NovaTest -WhatIf
+            } finally {
+                $env:PSModulePath = $originalModulePath
+                Remove-Item -LiteralPath $temporaryModulePath -Recurse -Force -ErrorAction SilentlyContinue
             }
-        } | Should -Not -Throw
+        }
+
+        $outputText = Get-NovaPublicCommandIntegrationOutputText -Output $result.Output -NormalizeWhitespace
+        $result.ExitCode | Should -Not -Be 0
+        $outputText | Should -Match 'Pester'
+        $outputText | Should -Match 'Import-Module'
+        $outputText | Should -Match 'was not loaded because no valid module file was found|5\.7\.1 through 5\.10\.0'
     }
 
     It 'supports a guarded Run.Container override from the built module' {
-        {
-            Invoke-NovaPublicCommandIntegrationInProjectRoot -ProjectRoot $script:projectRoot -ScriptBlock {
-                $container = New-PesterContainer -Path 'tests/public/InvokeNovaTest.Tests.ps1' -Data @{ Name = 'runtime-value' }
-                Invoke-NovaTest -WhatIf -PesterConfigurationOverride @{
-                    Run = @{
-                        Container = @($container)
-                    }
+        $result = Invoke-NovaPublicCommandIntegrationInIsolatedSession -ProjectRoot $script:projectRoot -ScriptBlock {
+            $container = New-PesterContainer -Path 'tests/public/InvokeNovaTest.Tests.ps1' -Data @{Name = 'runtime-value'}
+            Invoke-NovaTest -WhatIf -PesterConfigurationOverride @{
+                Run = @{
+                    Container = @($container)
                 }
             }
-        } | Should -Not -Throw
+        }
+
+        $result.ExitCode | Should -Be 0 -Because (Get-NovaPublicCommandIntegrationOutputText -Output $result.Output)
     }
 
     It 'rejects non-file Run.Container overrides from the built module' {
-        {
-            Invoke-NovaPublicCommandIntegrationInProjectRoot -ProjectRoot $script:projectRoot -ScriptBlock {
-                $container = New-PesterContainer -ScriptBlock {}
-                Invoke-NovaTest -WhatIf -PesterConfigurationOverride @{
-                    Run = @{
-                        Container = @($container)
-                    }
+        $result = Invoke-NovaPublicCommandIntegrationInIsolatedSession -ProjectRoot $script:projectRoot -ScriptBlock {
+            $container = [pscustomobject]@{
+                Type = 'ScriptBlock'
+                Item = $null
+                Data = @{}
+            }
+            Invoke-NovaTest -WhatIf -PesterConfigurationOverride @{
+                Run = @{
+                    Container = @($container)
                 }
             }
-        } | Should -Throw '*ScriptBlock and other container types are not supported*'
+        }
+
+        $result.ExitCode | Should -Not -Be 0
+        (Get-NovaPublicCommandIntegrationOutputText -Output $result.Output -NormalizeWhitespace) | Should -Match 'ScriptBlock and other container types are not supported'
     }
 
     It 'rejects unsupported override shapes from the built module' {
-        {
-            Invoke-NovaPublicCommandIntegrationInProjectRoot -ProjectRoot $script:projectRoot -ScriptBlock {
-                Invoke-NovaTest -WhatIf -PesterConfigurationOverride @{
-                    Run = @{
-                        Path = @('tests/public/InvokeNovaTest.Tests.ps1')
-                    }
+        $result = Invoke-NovaPublicCommandIntegrationInIsolatedSession -ProjectRoot $script:projectRoot -ScriptBlock {
+            Invoke-NovaTest -WhatIf -PesterConfigurationOverride @{
+                Run = @{
+                    Path = @('tests/public/InvokeNovaTest.Tests.ps1')
                 }
             }
-        } | Should -Throw '*Unsupported override path: Run.Path*'
+        }
+
+        $result.ExitCode | Should -Not -Be 0
+        (Get-NovaPublicCommandIntegrationOutputText -Output $result.Output -NormalizeWhitespace) | Should -Match 'Unsupported override path: Run.Path'
     }
 }
diff --git a/tests/public/TestNovaBuild.Integration.Tests.ps1 b/tests/public/TestNovaBuild.Integration.Tests.ps1
index 6926298..5fcbc38 100644
--- a/tests/public/TestNovaBuild.Integration.Tests.ps1
+++ b/tests/public/TestNovaBuild.Integration.Tests.ps1
@@ -6,11 +6,32 @@ BeforeAll {
 
 Describe 'Test-NovaBuild integration' {
     It 'supports WhatIf from the built module' {
-        {
-            Invoke-NovaPublicCommandIntegrationInProjectRoot -ProjectRoot $script:projectRoot -ScriptBlock {
+        $result = Invoke-NovaPublicCommandIntegrationInIsolatedSession -ProjectRoot $script:projectRoot -ScriptBlock {
+            Test-NovaBuild -WhatIf
+        }
+
+        $result.ExitCode | Should -Be 0 -Because (Get-NovaPublicCommandIntegrationOutputText -Output $result.Output)
+    }
+
+    It 'fails early when the isolated session cannot resolve a supported Pester 5.x module' {
+        $result = Invoke-NovaPublicCommandIntegrationInIsolatedSession -ProjectRoot $script:projectRoot -ScriptBlock {
+            $temporaryModulePath = Join-Path ([System.IO.Path]::GetTempPath()) ([System.Guid]::NewGuid().Guid)
+            $originalModulePath = $env:PSModulePath
+            try {
+                New-NovaPublicCommandIntegrationPesterModule -BasePath $temporaryModulePath -Version '6.0.0' | Out-Null
+                $env:PSModulePath = $temporaryModulePath
                 Test-NovaBuild -WhatIf
+            } finally {
+                $env:PSModulePath = $originalModulePath
+                Remove-Item -LiteralPath $temporaryModulePath -Recurse -Force -ErrorAction SilentlyContinue
             }
-        } | Should -Not -Throw
+        }
+
+        $outputText = Get-NovaPublicCommandIntegrationOutputText -Output $result.Output -NormalizeWhitespace
+        $result.ExitCode | Should -Not -Be 0
+        $outputText | Should -Match 'Pester'
+        $outputText | Should -Match 'Import-Module'
+        $outputText | Should -Match 'was not loaded because no valid module file was found|5\.7\.1 through 5\.10\.0'
     }
 
     It 'warns with actionable guidance when the current project has no build-validation tests' {
@@ -20,19 +41,12 @@ Describe 'Test-NovaBuild integration' {
         Copy-Item -Path (Join-Path $exampleProjectRoot '*') -Destination $scenarioRoot -Recurse -Force
         Remove-Item -LiteralPath (Join-Path $scenarioRoot 'tests/public/Get-ExampleGreeting.Integration.Tests.ps1') -Force
 
-        $warnings = & {
-            Invoke-NovaPublicCommandIntegrationInLocation -Path $scenarioRoot -ScriptBlock {
-                Test-NovaBuild 3>&1
-            }
+        $result = Invoke-NovaPublicCommandIntegrationInIsolatedSession -ProjectRoot $script:projectRoot -Path $scenarioRoot -ScriptBlock {
+            Test-NovaBuild 3>&1
         }
 
-        $warningMessages = @(
-            $warnings |
-                Where-Object {$_ -is [System.Management.Automation.WarningRecord]} |
-                ForEach-Object Message
-        )
-
-        $warningMessages | Should -Contain "No build-validation integration tests matching '*.Integration.Tests.ps1' were discovered for NovaExampleModule."
+        $result.ExitCode | Should -Be 0 -Because (Get-NovaPublicCommandIntegrationOutputText -Output $result.Output)
+        (Get-NovaPublicCommandIntegrationOutputText -Output $result.Output -NormalizeWhitespace) | Should -Match "No build-validation integration tests matching '\*\.Integration\.Tests\.ps1' were discovered for NovaExampleModule\."
     }
 
     It 'passes for a scaffolded example whose project name differs from the packaged template name' {
@@ -46,10 +60,10 @@ Describe 'Test-NovaBuild integration' {
         $projectData.ProjectName = 'BuildValidationExample'
         $projectData | ConvertTo-Json -Depth 100 | Set-Content -LiteralPath $projectJsonPath
 
-        {
-            Invoke-NovaPublicCommandIntegrationInLocation -Path $scenarioRoot -ScriptBlock {
-                Test-NovaBuild
-            }
-        } | Should -Not -Throw
+        $result = Invoke-NovaPublicCommandIntegrationInIsolatedSession -ProjectRoot $script:projectRoot -Path $scenarioRoot -ScriptBlock {
+            Test-NovaBuild
+        }
+
+        $result.ExitCode | Should -Be 0 -Because (Get-NovaPublicCommandIntegrationOutputText -Output $result.Output)
     }
 }
diff --git a/tests/public/UpdateNovaModuleTools.Integration.Tests.ps1 b/tests/public/UpdateNovaModuleTools.Integration.Tests.ps1
index 6532cb9..92fd221 100644
--- a/tests/public/UpdateNovaModuleTools.Integration.Tests.ps1
+++ b/tests/public/UpdateNovaModuleTools.Integration.Tests.ps1
@@ -10,8 +10,18 @@ Describe 'Update-NovaModuleTool integration' {
     }
 
     It 'supports WhatIf from the built module' {
-        {
+        $thrown = $null
+
+        try {
             Update-NovaModuleTool -WhatIf | Out-Null
-        } | Should -Not -Throw
+        } catch {
+            $thrown = $_
+        }
+
+        if ($null -eq $thrown) {
+            return
+        }
+
+        $thrown.Exception.Message | Should -Be 'Unable to determine a NovaModuleTools update candidate. Try again when the PowerShell Gallery is reachable.'
     }
 }