diff --git a/src/ObjCRuntime/Runtime.iOS.cs b/src/ObjCRuntime/Runtime.iOS.cs
index 818f1babf68c..0b8af7822081 100644
--- a/src/ObjCRuntime/Runtime.iOS.cs
+++ b/src/ObjCRuntime/Runtime.iOS.cs
@@ -40,13 +40,13 @@ public static partial class Runtime {
 		#error Unknown platform
 #endif
 
+#if !__MACCATALYST__
 		public static Arch Arch; // default: = Arch.DEVICE;
+#endif
 
 		unsafe static void InitializePlatform (InitializationOptions* options)
 		{
-#if __MACCATALYST__
-			Arch = Arch.SIMULATOR;
-#else
+#if !__MACCATALYST__
 			if (options->IsSimulator)
 				Arch = Arch.SIMULATOR;
 #endif
@@ -124,10 +124,12 @@ public static void StartWWAN (Uri uri)
 #endif // !COREBUILD
 	}
 
+#if !__MACCATALYST__
 	public enum Arch {
 		DEVICE,
 		SIMULATOR
 	}
+#endif
 }
 
 #endif // MONOMAC