--- a/js/src/jit/VMFunctions.cpp
+++ b/js/src/jit/VMFunctions.cpp
@@ -571,17 +571,16 @@ CreateThis(JSContext* cx, HandleObject c
 
     if (callee->is<JSFunction>()) {
         JSFunction* fun = &callee->as<JSFunction>();
         if (fun->isInterpreted() && fun->isConstructor()) {
             JSScript* script = fun->getOrCreateScript(cx);
             if (!script || !script->ensureHasTypes(cx))
                 return false;
             if (script->isDerivedClassConstructor()) {
-                MOZ_ASSERT(fun->isClassConstructor());
                 rval.set(MagicValue(JS_UNINITIALIZED_LEXICAL));
             } else {
                 JSObject* thisObj = CreateThisForFunction(cx, callee, newTarget, GenericObject);
                 if (!thisObj)
                     return false;
                 rval.set(ObjectValue(*thisObj));
             }
         }