diff --git a/interop/src/arkts/SerializerBase.ts b/interop/src/arkts/SerializerBase.ts
index fba25295ef18251acd322fa36aa2a2619705cf70..033a2bf48a2c53fe96a09fec8015fdbc01c60a05 100644
--- a/interop/src/arkts/SerializerBase.ts
+++ b/interop/src/arkts/SerializerBase.ts
@@ -79,10 +79,15 @@ export function runtimeType<T>(value: T): int32 {
     if (value instanceof Function)
         return RuntimeType.FUNCTION
 
-    if (value instanceof Object)
-        return RuntimeType.OBJECT
+    // slow workaround for enum
+    const typeName = typeof value
+    if (typeName == "number")
+      return RuntimeType.NUMBER
 
-    throw new Error(`bug: ${value} is ${typeof value}`)
+    if (typeName == "string")
+      return RuntimeType.STRING
+
+    return RuntimeType.OBJECT
 }
 
 export function toPeerPtr(value: object): pointer {