diff --git a/BREAKINGS.md b/BREAKINGS.md
index 99c8e493..1b2cca48 100644
--- a/BREAKINGS.md
+++ b/BREAKINGS.md
@@ -2,6 +2,30 @@
 
 This document outlines all breaking changes introduced in CTBase v0.18.0-beta compared to v0.17.4. Use this guide to migrate your code and understand the impact of these changes.
 
+## Breaking changes (0.25.0-beta)
+
+- **`NotProvided` / `NotProvidedType` removed from `CTBase.Options`.** They now live and are
+  exported **only** in `CTBase.Core`. `CTBase.Options.NotProvided` and
+  `CTBase.Options.NotProvidedType` no longer exist, and `using CTBase.Options` no longer
+  brings these names into scope.
+
+  **Migration:** replace `Options.NotProvided` → `Core.NotProvided` and
+  `Options.NotProvidedType` → `Core.NotProvidedType` (fully qualified: `CTBase.Core.NotProvided`).
+
+  ```julia
+  # before
+  using CTBase.Options
+  OptionDefinition(name=:x, type=Int, default=NotProvided)
+
+  # after
+  import CTBase.Core
+  using CTBase.Options
+  OptionDefinition(name=:x, type=Int, default=Core.NotProvided)
+  ```
+
+- `NotStored` / `NotStoredType` are unchanged and remain extraction-internal to
+  `CTBase.Options` (the defining file was renamed `not_provided.jl` → `not_stored.jl`).
+
 ## Non-breaking note (0.24.0-beta)
 
 - **Differentiation module**: Added comprehensive AD backend infrastructure for computing gradients
diff --git a/CHANGELOGS.md b/CHANGELOGS.md
index c34587b5..9313d700 100644
--- a/CHANGELOGS.md
+++ b/CHANGELOGS.md
@@ -5,6 +5,23 @@ All notable changes to CTBase will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.25.0-beta] - 2026-06-26
+
+### ⚠️ Breaking Changes
+
+- **NotProvided moved to Core (no re-export)**: `NotProvidedType` and `NotProvided` are now
+  defined and exported **only** from `CTBase.Core`. They are **no longer available** from
+  `CTBase.Options` — `CTBase.Options.NotProvided` / `CTBase.Options.NotProvidedType` no longer
+  exist. Replace any `Options.NotProvided` usage with `Core.NotProvided` (or
+  `CTBase.Core.NotProvided`).
+- `CTBase.Core.NotProvided` is the canonical ecosystem-wide "not provided" sentinel.
+
+### 🔄 Refactoring
+
+- `CTBase.Options` now only defines the extraction-internal `NotStored` / `NotStoredType`
+  sentinels (file renamed `not_provided.jl` → `not_stored.jl`). Internal Options/Strategies
+  code references `Core.NotProvidedType` directly.
+
 ## [0.24.0-beta] - 2026-06-25
 
 ### ✨ New Features
diff --git a/Project.toml b/Project.toml
index db0f3896..1ac08ed9 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,6 +1,6 @@
 name = "CTBase"
 uuid = "54762871-cc72-4466-b8e8-f6c8b58076cd"
-version = "0.24.0-beta"
+version = "0.25.0-beta"
 authors = ["Olivier Cots <olivier.cots@irit.fr>", "Jean-Baptiste Caillau <caillau@univ-cotedazur.fr>"]
 
 [deps]
diff --git a/src/Core/Core.jl b/src/Core/Core.jl
index 213949d0..87eba4a8 100644
--- a/src/Core/Core.jl
+++ b/src/Core/Core.jl
@@ -13,6 +13,7 @@ import DocStringExtensions: TYPEDEF, TYPEDSIGNATURES
 include("types.jl")
 include("tags.jl")
 include("caches.jl")
+include("not_provided.jl")
 include("default.jl")
 
 # Private utilities
@@ -27,6 +28,7 @@ include("display.jl")
 # Export public API
 export ctNumber, matrix2vec, to_out_of_place, make_coerce, @ensure
 export AbstractTag, AbstractCache
+export NotProvided, NotProvidedType
 export Style, Palette
 export DEFAULT_PALETTE, MONOCHROME_PALETTE, HIGH_CONTRAST_PALETTE
 export current_palette, set_palette!, set_color!, reset_palette!, show_palette
diff --git a/src/Core/not_provided.jl b/src/Core/not_provided.jl
new file mode 100644
index 00000000..8200a1fb
--- /dev/null
+++ b/src/Core/not_provided.jl
@@ -0,0 +1,39 @@
+"""
+$(TYPEDEF)
+
+Singleton type marking the absence of a provided value.
+
+Ecosystem-wide sentinel for "no default / argument not given". The canonical
+value is [`NotProvided`](@ref).
+
+See also: [`NotProvided`](@ref).
+"""
+struct NotProvidedType end
+
+"""
+    NotProvided
+
+Singleton instance of [`NotProvidedType`](@ref).
+
+The canonical "not provided" sentinel used across the control-toolbox ecosystem
+(option defaults, optional variable parameters, optional AD backends, …).
+
+# Example
+```julia-repl
+julia> using CTBase.Core
+
+julia> x = NotProvided
+NotProvided
+
+julia> x isa NotProvidedType
+true
+
+julia> x === NotProvided
+true
+```
+
+See also: [`NotProvidedType`](@ref).
+"""
+const NotProvided = NotProvidedType()
+
+Base.show(io::IO, ::NotProvidedType) = print(io, "NotProvided")
diff --git a/src/Options/Options.jl b/src/Options/Options.jl
index 37f37fad..fc55d455 100644
--- a/src/Options/Options.jl
+++ b/src/Options/Options.jl
@@ -18,14 +18,13 @@ import CTBase.Core
 import CTBase.Exceptions
 
 # Submodules
-include(joinpath(@__DIR__, "not_provided.jl"))
+include(joinpath(@__DIR__, "not_stored.jl"))
 include(joinpath(@__DIR__, "option_value.jl"))
 include(joinpath(@__DIR__, "option_definition.jl"))
 include(joinpath(@__DIR__, "extraction.jl"))
 
 # Public API
 
-export NotProvided, NotProvidedType
 export OptionValue, OptionDefinition, extract_option, extract_options, extract_raw_options
 export all_names, aliases
 export is_user, is_default, is_computed  # is_computed works for both OptionValue and OptionDefinition
diff --git a/src/Options/extraction.jl b/src/Options/extraction.jl
index a68a297b..66dd42c6 100644
--- a/src/Options/extraction.jl
+++ b/src/Options/extraction.jl
@@ -77,7 +77,7 @@ function extract_option(kwargs::NamedTuple, def::OptionDefinition)
     end
 
     # Not found - check if default is NotProvided
-    if def.default isa NotProvidedType
+    if def.default isa Core.NotProvidedType
         # No default and not provided by user - return NotStored to signal "don't store"
         return NotStored, kwargs
     end
@@ -223,7 +223,7 @@ builders to use their own defaults. Options with explicit `nothing` values are i
 opts = (backend = OptionValue(:optimized, :user), 
         show_time = OptionValue(false, :default),
         minimize = OptionValue(nothing, :default),
-        optional = OptionValue(NotProvided, :default))
+        optional = OptionValue(CTBase.Core.NotProvided, :default))
 
 extract_raw_options(opts)
 # (backend = :optimized, show_time = false, minimize = nothing)
@@ -236,7 +236,7 @@ function extract_raw_options(options::NamedTuple)
     for (k, v) in pairs(options)
         val = v isa OptionValue ? v.value : v
         # Filter out NotProvided values, but keep nothing values
-        if !(val isa NotProvidedType)
+        if !(val isa Core.NotProvidedType)
             raw_opts_dict[k] = val
         end
     end
diff --git a/src/Options/not_provided.jl b/src/Options/not_provided.jl
deleted file mode 100644
index e8ef882b..00000000
--- a/src/Options/not_provided.jl
+++ /dev/null
@@ -1,98 +0,0 @@
-# NotProvided sentinel type
-#
-# Singleton type representing the absence of a default value for an option.
-
-"""
-$(TYPEDEF)
-
-Singleton type representing the absence of a default value for an option.
-
-This type is used to distinguish between:
-- `default = NotProvided`: No default value, option must be provided by user or not stored
-- `default = nothing`: The default value is explicitly `nothing`
-
-# Example
-```julia
-# Option with no default - won't be stored if not provided
-opt1 = OptionDefinition(
-    name = :minimize,
-    type = Union{Bool, Nothing},
-    default = NotProvided,
-    description = "Whether to minimize"
-)
-
-# Option with explicit nothing default - will be stored as nothing
-opt2 = OptionDefinition(
-    name = :backend,
-    type = Union{Nothing, KernelAbstractions.Backend},
-    default = nothing,
-    description = "Execution backend"
-)
-```
-
-See also: `OptionDefinition`, `extract_options`
-"""
-struct NotProvidedType end
-
-"""
-    NotProvided
-
-Singleton instance of `NotProvidedType`.
-
-Use this as the default value in `OptionDefinition` to indicate
-that an option has no default value and should not be stored if not provided
-by the user.
-
-# Example
-```julia-repl
-julia> using CTBase.Options
-
-julia> def = OptionDefinition(
-           name = :optional_param,
-           type = Any,
-           default = NotProvided,
-           description = "Optional parameter"
-       )
-
-julia> # If user doesn't provide it, it won't be stored
-julia> opts, _ = extract_options((other=1,), [def])
-julia> haskey(opts, :optional_param)
-false
-```
-"""
-const NotProvided = NotProvidedType()
-
-# Pretty printing
-Base.show(io::IO, ::NotProvidedType) = print(io, "NotProvided")
-
-"""
-$(TYPEDEF)
-
-Internal sentinel type used by the option extraction system to signal that an option
-should not be stored in the instance.
-
-This is returned by `extract_option` when an option has `NotProvided` as its
-default and was not provided by the user.
-
-# Note
-This type is internal to the Options module and should not be used directly by users.
-Use `NotProvided` instead.
-
-See also: `NotProvided`, `extract_option`
-"""
-struct NotStoredType end
-
-"""
-    NotStored
-
-Internal singleton instance of `NotStoredType`.
-
-Used internally by the option extraction system to signal that an option should not
-be stored. This is distinct from `nothing` which is a valid option value.
-
-See also: `NotProvided`, `extract_option`
-"""
-const NotStored = NotStoredType()
-
-# Pretty printing
-Base.show(io::IO, ::NotStoredType) = print(io, "NotStored")
diff --git a/src/Options/not_stored.jl b/src/Options/not_stored.jl
new file mode 100644
index 00000000..d63fdf9e
--- /dev/null
+++ b/src/Options/not_stored.jl
@@ -0,0 +1,30 @@
+"""
+$(TYPEDEF)
+
+Internal sentinel type used by the option extraction system to signal that an option
+should not be stored in the instance.
+
+This is returned by `extract_option` when an option has [`CTBase.Core.NotProvided`](@ref)
+as its default and was not provided by the user.
+
+# Note
+This type is internal to the Options module and should not be used directly by users.
+Use [`CTBase.Core.NotProvided`](@ref) instead.
+
+See also: [`CTBase.Core.NotProvided`](@ref), [`extract_option`](@ref).
+"""
+struct NotStoredType end
+
+"""
+    NotStored
+
+Internal singleton instance of [`NotStoredType`](@ref).
+
+Used internally by the option extraction system to signal that an option should not
+be stored. This is distinct from `nothing` which is a valid option value.
+
+See also: [`CTBase.Core.NotProvided`](@ref), [`extract_option`](@ref).
+"""
+const NotStored = NotStoredType()
+
+Base.show(io::IO, ::NotStoredType) = print(io, "NotStored")
diff --git a/src/Options/option_definition.jl b/src/Options/option_definition.jl
index a6796c20..698ec2ef 100644
--- a/src/Options/option_definition.jl
+++ b/src/Options/option_definition.jl
@@ -85,7 +85,7 @@ struct OptionDefinition{T}
         computed::Bool=false,
     ) where {T}
         # Validate with custom validator if provided (skip for NotProvided)
-        if validator !== nothing && !(default isa NotProvidedType)
+        if validator !== nothing && !(default isa Core.NotProvidedType)
             try
                 validator(default)
             catch e
@@ -152,7 +152,7 @@ julia> # No default - creates NotProvidedType
 julia> def3 = OptionDefinition(
            name = :input_file,
            type = String,
-           default = NotProvided,
+           default = CTBase.Core.NotProvided,
            description = "Input file path"
        )
 OptionDefinition{NotProvidedType}(...)
@@ -270,7 +270,7 @@ julia> using CTBase.Options
 julia> def = _construct_option_definition(
            :input_file,
            String,
-           NotProvided,
+           CTBase.Core.NotProvided,
            "Input file path",
            (:input,)
        )
@@ -285,13 +285,13 @@ See also: `OptionDefinition`, `NotProvided`, `is_required`
 function _construct_option_definition(
     name::Symbol,
     type::Type,
-    default::NotProvidedType,
+    default::Core.NotProvidedType,
     description::String,
     aliases::Tuple{Vararg{Symbol}},
     validator::Union{Function,Nothing},
     computed::Bool,
 )
-    return OptionDefinition{NotProvidedType}(;
+    return OptionDefinition{Core.NotProvidedType}(;
         name=name,
         type=type,
         default=default,
@@ -543,7 +543,7 @@ Returns `true` when the default value is `NotProvided`.
 ```julia-repl
 julia> using CTBase.Options
 
-julia> def = OptionDefinition(name=:input, type=String, default=NotProvided,
+julia> def = OptionDefinition(name=:input, type=String, default=CTBase.Core.NotProvided,
                           description="Input file")
 OptionDefinition{NotProvidedType}(...)
 
@@ -553,7 +553,7 @@ true
 
 See also: `has_default`, `default`
 """
-is_required(def::OptionDefinition) = def.default isa NotProvidedType
+is_required(def::OptionDefinition) = def.default isa Core.NotProvidedType
 
 """
 $(TYPEDSIGNATURES)
@@ -579,7 +579,7 @@ true
 
 See also: `is_required`, `default`
 """
-has_default(def::OptionDefinition) = !(def.default isa NotProvidedType)
+has_default(def::OptionDefinition) = !(def.default isa Core.NotProvidedType)
 
 """
 $(TYPEDSIGNATURES)
diff --git a/test/suite/options/test_coverage_options.jl b/test/suite/options/test_coverage_options.jl
index 4441fc59..004bc11d 100644
--- a/test/suite/options/test_coverage_options.jl
+++ b/test/suite/options/test_coverage_options.jl
@@ -3,6 +3,7 @@ module TestCoverageOptions
 using Test: Test
 import CTBase.Exceptions
 import CTBase.Options
+import CTBase.Core
 import CTBase.Strategies
 
 const VERBOSE = isdefined(Main, :TestData) ? Main.TestData.VERBOSE : true
@@ -43,7 +44,7 @@ function test_coverage_options()
 
         Test.@testset "NotProvided display" begin
             buf = IOBuffer()
-            show(buf, Options.NotProvided)
+            show(buf, Core.NotProvided)
             Test.@test String(take!(buf)) == "NotProvided"
         end
 
diff --git a/test/suite/options/test_not_provided.jl b/test/suite/options/test_not_provided.jl
index 6e25411d..9ed6967e 100644
--- a/test/suite/options/test_not_provided.jl
+++ b/test/suite/options/test_not_provided.jl
@@ -2,6 +2,7 @@ module TestOptionsNotProvided
 
 using Test: Test
 import CTBase.Options
+import CTBase.Core
 const VERBOSE = isdefined(Main, :TestData) ? Main.TestData.VERBOSE : true
 const SHOWTIMING = isdefined(Main, :TestData) ? Main.TestData.SHOWTIMING : true
 
@@ -13,9 +14,9 @@ Test the NotProvided type and its behavior in the option system.
 function test_not_provided()
     Test.@testset "NotProvided Type Tests" verbose = VERBOSE showtiming = SHOWTIMING begin
         Test.@testset "NotProvided Basic Properties" begin
-            Test.@test Options.NotProvided isa Options.NotProvidedType
-            Test.@test typeof(Options.NotProvided) == Options.NotProvidedType
-            Test.@test string(Options.NotProvided) == "NotProvided"
+            Test.@test Core.NotProvided isa Core.NotProvidedType
+            Test.@test typeof(Core.NotProvided) == Core.NotProvidedType
+            Test.@test string(Core.NotProvided) == "NotProvided"
         end
 
         Test.@testset "OptionDefinition with NotProvided" begin
@@ -23,12 +24,12 @@ function test_not_provided()
             def_not_provided = Options.OptionDefinition(
                 name=:optional_param,
                 type=Union{Int,Nothing},
-                default=Options.NotProvided,
+                default=Core.NotProvided,
                 description="Optional parameter",
             )
 
-            Test.@test Options.default(def_not_provided) === Options.NotProvided
-            Test.@test Options.default(def_not_provided) isa Options.NotProvidedType
+            Test.@test Options.default(def_not_provided) === Core.NotProvided
+            Test.@test Options.default(def_not_provided) isa Core.NotProvidedType
 
             # Option with nothing default (different!)
             def_nothing = Options.OptionDefinition(
@@ -39,14 +40,14 @@ function test_not_provided()
             )
 
             Test.@test Options.default(def_nothing) === nothing
-            Test.@test !(Options.default(def_nothing) isa Options.NotProvidedType)
+            Test.@test !(Options.default(def_nothing) isa Core.NotProvidedType)
         end
 
         Test.@testset "extract_option with NotProvided" begin
             def = Options.OptionDefinition(
                 name=:optional,
                 type=Union{Int,Nothing},
-                default=Options.NotProvided,
+                default=Core.NotProvided,
                 description="Optional",
             )
 
@@ -79,7 +80,7 @@ function test_not_provided()
                 Options.OptionDefinition(
                     name=:optional,
                     type=Union{Int,Nothing},
-                    default=Options.NotProvided,
+                    default=Core.NotProvided,
                     description="Optional",
                 ),
                 Options.OptionDefinition(
@@ -104,7 +105,7 @@ function test_not_provided()
 
             # Verify NO NotProvidedType in extracted values
             for (k, v) in pairs(extracted)
-                Test.@test !(Options.value(v) isa Options.NotProvidedType)
+                Test.@test !(Options.value(v) isa Core.NotProvidedType)
             end
         end
 
@@ -120,7 +121,7 @@ function test_not_provided()
                 Options.OptionDefinition(
                     name=:minimize,
                     type=Union{Bool,Nothing},
-                    default=Options.NotProvided,
+                    default=Core.NotProvided,
                     description="Minimize with NotProvided",
                 ),
             ]
@@ -168,7 +169,7 @@ function test_not_provided()
 
             # Verify NO NotProvidedType in raw values
             for (k, v) in pairs(stored_options)
-                Test.@test !(Options.value(v) isa Options.NotProvidedType)
+                Test.@test !(Options.value(v) isa Core.NotProvidedType)
             end
         end
 
@@ -181,7 +182,7 @@ function test_not_provided()
                 minimize=Options.OptionDefinition(
                     name=:minimize,
                     type=Union{Bool,Nothing},
-                    default=Options.NotProvided,
+                    default=Core.NotProvided,
                     description="Minimize flag",
                 ),
                 backend=Options.OptionDefinition(
@@ -202,7 +203,7 @@ function test_not_provided()
 
             # Verify NO NotProvidedType in extracted
             for (k, v) in pairs(extracted)
-                Test.@test !(v.value isa Options.NotProvidedType)
+                Test.@test !(v.value isa Core.NotProvidedType)
             end
 
             # Extract raw options (what gets passed to builder)
@@ -215,7 +216,7 @@ function test_not_provided()
 
             # Verify NO NotProvidedType in raw
             for (k, v) in pairs(raw)
-                Test.@test !(v isa Options.NotProvidedType)
+                Test.@test !(v isa Core.NotProvidedType)
             end
         end
     end
diff --git a/test/suite/options/test_option_definition.jl b/test/suite/options/test_option_definition.jl
index 7ec1c92f..c862c981 100644
--- a/test/suite/options/test_option_definition.jl
+++ b/test/suite/options/test_option_definition.jl
@@ -3,6 +3,7 @@ module TestOptionsOptionDefinition
 using Test: Test
 import CTBase.Exceptions
 import CTBase.Options
+import CTBase.Core
 const VERBOSE = isdefined(Main, :TestData) ? Main.TestData.VERBOSE : true
 const SHOWTIMING = isdefined(Main, :TestData) ? Main.TestData.SHOWTIMING : true
 
@@ -147,7 +148,7 @@ function test_option_definition()
             def_required = Options.OptionDefinition(
                 name=:input,
                 type=String,
-                default=Options.NotProvided,
+                default=Core.NotProvided,
                 description="Input file",
             )
             def_optional = Options.OptionDefinition(
@@ -211,17 +212,17 @@ function test_option_definition()
                 def = Options._construct_option_definition(
                     :input_file,
                     String,
-                    Options.NotProvided,
+                    Core.NotProvided,
                     "Input file path",
                     (:input,),
                     nothing,
                     false,
                 )
 
-                Test.@test def isa Options.OptionDefinition{Options.NotProvidedType}
+                Test.@test def isa Options.OptionDefinition{Core.NotProvidedType}
                 Test.@test Options.name(def) == :input_file
                 Test.@test Options.type(def) == String
-                Test.@test Options.default(def) === Options.NotProvided
+                Test.@test Options.default(def) === Core.NotProvided
                 Test.@test Options.description(def) == "Input file path"
                 Test.@test Options.aliases(def) == (:input,)
                 Test.@test Options.validator(def) === nothing
@@ -331,11 +332,11 @@ function test_option_definition()
                 def_not_provided = Options.OptionDefinition(
                     name=:input_file,
                     type=String,
-                    default=Options.NotProvided,
+                    default=Core.NotProvided,
                     description="Input file",
                 )
                 Test.@test def_not_provided isa
-                    Options.OptionDefinition{Options.NotProvidedType}
+                    Options.OptionDefinition{Core.NotProvidedType}
                 Test.@test Options.type(def_not_provided) == String  # type is preserved
 
                 # Test that public constructor with concrete value creates correct type
@@ -423,7 +424,7 @@ function test_option_definition()
             required_def = Options.OptionDefinition(
                 name=:input,
                 type=String,
-                default=Options.NotProvided,
+                default=Core.NotProvided,
                 description="Input file",
             )
             Test.@test Options.has_default(required_def) === false
@@ -608,7 +609,7 @@ Test.@testset "Getters and introspection" begin
     Test.@test Options.has_validator(def) === true
 
     required_def = Options.OptionDefinition(
-        name=:input, type=String, default=Options.NotProvided, description="Input file"
+        name=:input, type=String, default=Core.NotProvided, description="Input file"
     )
     Test.@test Options.has_default(required_def) === false
     Test.@test Options.is_required(required_def) === true
diff --git a/test/suite/options/test_options.jl b/test/suite/options/test_options.jl
index ecf071ba..451c91f8 100644
--- a/test/suite/options/test_options.jl
+++ b/test/suite/options/test_options.jl
@@ -4,6 +4,7 @@ using Test: Test
 import CTBase.Exceptions
 using CTBase: CTBase
 import CTBase.Options
+import CTBase.Core
 using CTBase.Options  # For testing exported symbols
 
 const VERBOSE = isdefined(Main, :TestData) ? Main.TestData.VERBOSE : true
@@ -38,7 +39,7 @@ function test_options()
 
             # Test exported types
             Test.@testset "Exported Types" begin
-                for T in (NotProvidedType, OptionValue, OptionDefinition)
+                for T in (OptionValue, OptionDefinition)
                     Test.@testset "$(nameof(T))" begin
                         Test.@test isdefined(Options, nameof(T))
                         Test.@test isdefined(CurrentModule, nameof(T))
@@ -47,14 +48,12 @@ function test_options()
                 end
             end
 
-            # Test exported constants
-            Test.@testset "Exported Constants" begin
-                for c in (:NotProvided,)
-                    Test.@testset "$c" begin
-                        Test.@test isdefined(Options, c)
-                        Test.@test isdefined(CurrentModule, c)
-                    end
-                end
+            # NotProvided / NotProvidedType live in CTBase.Core, not in Options
+            Test.@testset "NotProvided moved to Core" begin
+                Test.@test isdefined(Core, :NotProvided)
+                Test.@test isdefined(Core, :NotProvidedType)
+                Test.@test !isdefined(Options, :NotProvided)
+                Test.@test !isdefined(Options, :NotProvidedType)
             end
 
             # Test exported functions
@@ -95,7 +94,7 @@ function test_options()
         Test.@testset "NotProvided and NotStored" begin
             Test.@testset "NotProvided display" begin
                 buf = IOBuffer()
-                show(buf, Options.NotProvided)
+                show(buf, Core.NotProvided)
                 Test.@test String(take!(buf)) == "NotProvided"
             end
 
@@ -263,7 +262,7 @@ function test_options()
                 opt_def_no_default = Options.OptionDefinition(
                     name=:required_option,
                     type=Int,
-                    default=Options.NotProvided,
+                    default=Core.NotProvided,
                     description="Required option",
                 )
 
@@ -316,7 +315,7 @@ function test_options()
                 opt_def_no_default = Options.OptionDefinition(
                     name=:required_option,
                     type=Int,
-                    default=Options.NotProvided,
+                    default=Core.NotProvided,
                     description="Required option",
                 )
                 options = NamedTuple()
@@ -339,7 +338,7 @@ function test_options()
                     Options.OptionDefinition(
                         name=:option3,
                         type=Float64,
-                        default=Options.NotProvided,
+                        default=Core.NotProvided,
                         description="Third option (required)",
                     ),
                 ]
diff --git a/test/suite/options/test_options_value.jl b/test/suite/options/test_options_value.jl
index 12f05d68..48f299fa 100644
--- a/test/suite/options/test_options_value.jl
+++ b/test/suite/options/test_options_value.jl
@@ -4,6 +4,7 @@ using Test: Test
 import CTBase.Exceptions
 using CTBase: CTBase
 import CTBase.Options
+import CTBase.Core
 
 const VERBOSE = isdefined(Main, :TestData) ? Main.TestData.VERBOSE : true
 const SHOWTIMING = isdefined(Main, :TestData) ? Main.TestData.SHOWTIMING : true
@@ -18,7 +19,6 @@ function test_options_value()
         Test.@testset "Exports verification" begin
             Test.@test isdefined(CTBase, :Options)
             Test.@test isdefined(Options, :OptionValue)
-            Test.@test isdefined(Options, :NotProvided)
             Test.@test isdefined(Options, :value)
             Test.@test isdefined(Options, :source)
             Test.@test isdefined(Options, :is_user)
diff --git a/test/suite/strategies/test_utilities.jl b/test/suite/strategies/test_utilities.jl
index b0b5493e..bf6a2fb6 100644
--- a/test/suite/strategies/test_utilities.jl
+++ b/test/suite/strategies/test_utilities.jl
@@ -3,6 +3,7 @@ module TestStrategiesUtilities
 using Test: Test
 import CTBase.Strategies
 import CTBase.Options
+import CTBase.Core
 
 const VERBOSE = isdefined(Main, :TestData) ? Main.TestData.VERBOSE : true
 const SHOWTIMING = isdefined(Main, :TestData) ? Main.TestData.SHOWTIMING : true
@@ -372,7 +373,7 @@ function test_utilities()
                 # Create StrategyOptions with NotProvided value
                 opts = Strategies.StrategyOptions(
                     max_iter=Options.OptionValue(500, :user),
-                    optional=Options.OptionValue(Options.NotProvided, :default),
+                    optional=Options.OptionValue(Core.NotProvided, :default),
                 )
 
                 # Convert to Dict