diff --git a/src/coreclr/tools/Common/TypeSystem/IL/NativeAotILProvider.cs b/src/coreclr/tools/Common/TypeSystem/IL/NativeAotILProvider.cs
index 5bbde912ee987b..fcd5925c258985 100644
--- a/src/coreclr/tools/Common/TypeSystem/IL/NativeAotILProvider.cs
+++ b/src/coreclr/tools/Common/TypeSystem/IL/NativeAotILProvider.cs
@@ -369,7 +369,9 @@ public override MethodIL GetMethodIL(MethodDesc method)
                 if (wrappedIL == null)
                     return null;
 
-                return new AsyncMethodIL(asyncVariantImpl, wrappedIL);
+                return wrappedIL is EcmaMethodIL ecmaIL
+                    ? new EcmaAsyncMethodIL(asyncVariantImpl, ecmaIL)
+                    : new AsyncMethodIL(asyncVariantImpl, wrappedIL);
             }
             else
             {
@@ -378,7 +380,7 @@ public override MethodIL GetMethodIL(MethodDesc method)
             }
         }
 
-        private sealed class AsyncMethodIL : MethodIL
+        private class AsyncMethodIL : MethodIL
         {
             private readonly AsyncMethodVariant _variant;
             private readonly MethodIL _wrappedIL;
@@ -398,5 +400,16 @@ public AsyncMethodIL(AsyncMethodVariant variant, MethodIL wrappedIL)
             public override bool IsInitLocals => _wrappedIL.IsInitLocals;
             public override int MaxStack => _wrappedIL.MaxStack;
         }
+
+        private sealed class EcmaAsyncMethodIL : AsyncMethodIL, IEcmaMethodIL
+        {
+            public EcmaAsyncMethodIL(AsyncMethodVariant variant, EcmaMethodIL wrappedIL)
+                : base(variant, wrappedIL)
+            {
+                Module = wrappedIL.Module;
+            }
+
+            public IEcmaModule Module { get; }
+        }
     }
 }
diff --git a/src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/SubstitutedILProvider.cs b/src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/SubstitutedILProvider.cs
index 4c15e385bb0a9e..e1b1d9db36d8d8 100644
--- a/src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/SubstitutedILProvider.cs
+++ b/src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/SubstitutedILProvider.cs
@@ -629,10 +629,10 @@ public MethodIL GetMethodILWithInlinedSubstitutions(MethodIL method)
                 debugInfo = new SubstitutedDebugInformation(debugInfo, sequencePoints.ToArray());
             }
 
-            // We only optimize EcmaMethods because there we can find out the highest string token RID
+            // We only optimize IL backed by an ECMA module because we can find the highest string token RID
             // in use.
             ArrayBuilder<string> newStrings = default;
-            if (hasGetResourceStringCall && method.GetMethodILDefinition() is EcmaMethodIL ecmaMethodIL)
+            if (hasGetResourceStringCall && method.GetMethodILDefinition() is IEcmaMethodIL ecmaMethodIL)
             {
                 // We're going to inject new string tokens. Start where the last token of the module left off.
                 // We don't need this token to be globally unique because all token resolution happens in the context
@@ -1182,7 +1182,7 @@ public override object GetObject(int token, NotFoundBehavior notFoundBehavior)
             {
                 // If this is a string token, it could be one of the new string tokens we injected.
                 if ((token >>> 24) == TokenTypeString
-                    && _wrappedMethodIL.GetMethodILDefinition() is EcmaMethodIL ecmaMethodIL)
+                    && _wrappedMethodIL.GetMethodILDefinition() is IEcmaMethodIL ecmaMethodIL)
                 {
                     int rid = token & 0xFFFFFF;
                     int maxRealTokenRid = ecmaMethodIL.Module.MetadataReader.GetHeapSize(HeapIndex.UserString);