diff --git a/js/src/jsapi.cpp b/js/src/jsapi.cpp
index 2fbf2c6a2f0c..b6a9fd7929ff 100644
--- a/js/src/jsapi.cpp
+++ b/js/src/jsapi.cpp
@@ -1374,11 +1374,8 @@ JS_GetClassPrototype(JSContext *cx, JSProtoKey key, MutableHandleObject objp)
 }
 
 JS_PUBLIC_API(JSProtoKey)
-JS_IdentifyClassPrototype(JSContext *cx, JSObject *obj)
+JS_IdentifyClassPrototype(JSObject *obj)
 {
-    AssertHeapIsIdle(cx);
-    CHECK_REQUEST(cx);
-    assertSameCompartment(cx, obj);
     JS_ASSERT(!obj->is<CrossCompartmentWrapperObject>());
     return js_IdentifyClassPrototype(obj);
 }
diff --git a/js/src/jsapi.h b/js/src/jsapi.h
index 0463b64bb07e..aec1f19bc92e 100644
--- a/js/src/jsapi.h
+++ b/js/src/jsapi.h
@@ -1796,7 +1796,7 @@ extern JS_PUBLIC_API(bool)
 JS_GetClassPrototype(JSContext *cx, JSProtoKey key, JS::MutableHandle<JSObject*> objp);
 
 extern JS_PUBLIC_API(JSProtoKey)
-JS_IdentifyClassPrototype(JSContext *cx, JSObject *obj);
+JS_IdentifyClassPrototype(JSObject *obj);
 
 extern JS_PUBLIC_API(JSProtoKey)
 JS_IdToProtoKey(JSContext *cx, JS::HandleId id);
diff --git a/js/xpconnect/wrappers/ChromeObjectWrapper.cpp b/js/xpconnect/wrappers/ChromeObjectWrapper.cpp
index e4b52e152fa2..99110413e44e 100644
--- a/js/xpconnect/wrappers/ChromeObjectWrapper.cpp
+++ b/js/xpconnect/wrappers/ChromeObjectWrapper.cpp
@@ -36,7 +36,7 @@ PropIsFromStandardPrototype(JSContext *cx, JS::MutableHandle<JSPropertyDescripto
     MOZ_ASSERT(desc.object());
     RootedObject unwrapped(cx, js::UncheckedUnwrap(desc.object()));
     JSAutoCompartment ac(cx, unwrapped);
-    return JS_IdentifyClassPrototype(cx, unwrapped) != JSProto_Null;
+    return JS_IdentifyClassPrototype(unwrapped) != JSProto_Null;
 }
 
 // Note that we're past the policy enforcement stage, here, so we can query
diff --git a/js/xpconnect/wrappers/WrapperFactory.cpp b/js/xpconnect/wrappers/WrapperFactory.cpp
index 749d96f36562..70cf822e13a0 100644
--- a/js/xpconnect/wrappers/WrapperFactory.cpp
+++ b/js/xpconnect/wrappers/WrapperFactory.cpp
@@ -174,7 +174,7 @@ WrapperFactory::PrepareForWrapping(JSContext *cx, HandleObject scope,
         JSProtoKey key = JSProto_Null;
         {
             JSAutoCompartment ac(cx, obj);
-            key = JS_IdentifyClassPrototype(cx, obj);
+            key = JS_IdentifyClassPrototype(obj);
         }
         if (key != JSProto_Null) {
             RootedObject homeProto(cx);