diff --git a/docs/coding-guidelines/breaking-change-rules.md b/docs/coding-guidelines/breaking-change-rules.md
index 4b8c396d57c15a..dd5ac5d550d0b9 100644
--- a/docs/coding-guidelines/breaking-change-rules.md
+++ b/docs/coding-guidelines/breaking-change-rules.md
@@ -169,6 +169,8 @@ Breaking Change Rules
 
 * Changing a `struct` type to a `ref struct` type and vice versa
 
+* Changing a `struct` type to an `enum` type and vice versa
+
 * Changing the underlying type of an enum
 
     This is a compile-time and behavioral breaking change as well as a binary breaking change which can make attribute arguments unparsable.
diff --git a/src/coreclr/tools/aot/ILCompiler.ReadyToRun.Tests/TestCases/CastFolding/CastFolding.cs b/src/coreclr/tools/aot/ILCompiler.ReadyToRun.Tests/TestCases/CastFolding/CastFolding.cs
index 4999c441c37b51..db5767f789e6ba 100644
--- a/src/coreclr/tools/aot/ILCompiler.ReadyToRun.Tests/TestCases/CastFolding/CastFolding.cs
+++ b/src/coreclr/tools/aot/ILCompiler.ReadyToRun.Tests/TestCases/CastFolding/CastFolding.cs
@@ -86,6 +86,9 @@ public static class CastFolding
     [MethodImpl(MethodImplOptions.NoInlining)]
     public static bool StructIsOtherStruct(SourceStruct s) => (object)s is TargetStruct;
 
+    [MethodImpl(MethodImplOptions.NoInlining)]
+    public static bool StructIsEnum(SourceStruct s) => (object)s is Enum;
+
     [MethodImpl(MethodImplOptions.NoInlining)]
     public static bool StructIsInterface(ControlStruct s) => (object)s is INotImplemented;
 
diff --git a/src/coreclr/tools/aot/ILCompiler.ReadyToRun.Tests/TestCases/R2RTestSuites.cs b/src/coreclr/tools/aot/ILCompiler.ReadyToRun.Tests/TestCases/R2RTestSuites.cs
index 0c350206e0b48d..3fb54a73887dfb 100644
--- a/src/coreclr/tools/aot/ILCompiler.ReadyToRun.Tests/TestCases/R2RTestSuites.cs
+++ b/src/coreclr/tools/aot/ILCompiler.ReadyToRun.Tests/TestCases/R2RTestSuites.cs
@@ -649,6 +649,7 @@ void Validate(ReadyToRunReader reader)
             Assert.False(importedTypes.Contains("byte"), diagnostic);
             Assert.False(importedTypes.Contains("SourceStruct"), diagnostic);
             Assert.False(importedTypes.Contains("TargetStruct"), diagnostic);
+            Assert.False(importedTypes.Contains("System.Enum"), diagnostic);
 
             // Casts to interfaces fold only when every type in the hierarchy is in the version bubble,
             // which includes System.Object and System.ValueType only with the framework in the bubble.
diff --git a/src/coreclr/tools/aot/ILCompiler.ReadyToRun/JitInterface/CorInfoImpl.ReadyToRun.cs b/src/coreclr/tools/aot/ILCompiler.ReadyToRun/JitInterface/CorInfoImpl.ReadyToRun.cs
index d8f5707fd0d927..548d5751971375 100644
--- a/src/coreclr/tools/aot/ILCompiler.ReadyToRun/JitInterface/CorInfoImpl.ReadyToRun.cs
+++ b/src/coreclr/tools/aot/ILCompiler.ReadyToRun/JitInterface/CorInfoImpl.ReadyToRun.cs
@@ -3972,8 +3972,8 @@ private bool IsNegativeCastResultVersionResilient(TypeDesc fromType, TypeDesc to
             if (fromType.HasTypeEquivalence || toType.HasTypeEquivalence)
                 return false;
 
-            // A value type can gain interfaces (or become an enum), but its other cast targets are fixed.
-            if (fromType.IsValueType && !toType.IsInterface && !toType.IsWellKnownType(WellKnownType.Enum))
+            // A value type can gain interfaces, but its other cast targets are fixed.
+            if (fromType.IsValueType && !toType.IsInterface)
                 return true;
 
             // Otherwise every type that decides the cast must version with this code. Array and variant casts