diff --git a/src/DiffEngine/Guard.cs b/src/DiffEngine/Guard.cs
index 8ce175ef..b6360b70 100644
--- a/src/DiffEngine/Guard.cs
+++ b/src/DiffEngine/Guard.cs
@@ -1,8 +1,8 @@
 static class Guard
 {
-    public static void AgainstNegativeAndZero(int value, string argumentName)
+    public static void AgainstNegative(int value, string argumentName)
     {
-        if (value <= 0)
+        if (value < 0)
         {
             throw new ArgumentOutOfRangeException(argumentName);
         }
diff --git a/src/DiffEngine/MaxInstance.cs b/src/DiffEngine/MaxInstance.cs
index 57edb7a0..3a14d6cb 100644
--- a/src/DiffEngine/MaxInstance.cs
+++ b/src/DiffEngine/MaxInstance.cs
@@ -33,14 +33,14 @@ static int GetMaxInstances() =>
 
     public static void SetForAppDomain(int value)
     {
-        Guard.AgainstNegativeAndZero(value, nameof(value));
+        Guard.AgainstNegative(value, nameof(value));
         appDomainMaxInstancesToLaunch = value;
         ResetCapturedValue();
     }
 
     public static void SetForUser(int value)
     {
-        Guard.AgainstNegativeAndZero(value, nameof(value));
+        Guard.AgainstNegative(value, nameof(value));
         EnvironmentHelper.Set("DiffEngine_MaxInstances", value.ToString());
         ResetCapturedValue();
     }
diff --git a/src/DiffEngineTray/Settings/OptionsForm.Designer.cs b/src/DiffEngineTray/Settings/OptionsForm.Designer.cs
index 0da00b15..8343bd6d 100644
--- a/src/DiffEngineTray/Settings/OptionsForm.Designer.cs
+++ b/src/DiffEngineTray/Settings/OptionsForm.Designer.cs
@@ -244,7 +244,7 @@ void InitializeComponent()
         this.maxInstancesNumericUpDown.Margin = new System.Windows.Forms.Padding(5);
         this.maxInstancesNumericUpDown.Minimum = new decimal(new int[]
         {
-            1,
+            0,
             0,
             0,
             0
@@ -254,7 +254,7 @@ void InitializeComponent()
         this.maxInstancesNumericUpDown.TabIndex = 0;
         this.maxInstancesNumericUpDown.Value = new decimal(new int[]
         {
-            1,
+            0,
             0,
             0,
             0
diff --git a/src/Directory.Build.props b/src/Directory.Build.props
index 6051fa93..8ce705d1 100644
--- a/src/Directory.Build.props
+++ b/src/Directory.Build.props
@@ -2,7 +2,7 @@
 <Project>
   <PropertyGroup>
     <NoWarn>CS1591;CS0649;NU1608;NU1109</NoWarn>
-    <Version>16.7.1</Version>
+    <Version>16.7.2</Version>
     <AssemblyVersion>1.0.0</AssemblyVersion>
     <PackageTags>Testing, Snapshot, Diff, Compare</PackageTags>
     <Description>Launches diff tools based on file extensions. Designed to be consumed by snapshot testing libraries.</Description>