--- a/js/src/vm/Debugger.cpp
+++ b/js/src/vm/Debugger.cpp
@@ -6948,26 +6948,26 @@ DebuggerObject_getGlobal(JSContext* cx, 
 
 static bool
 null(CallArgs& args)
 {
     args.rval().setNull();
     return true;
 }
 
-/* static */ JSObject*
+/* static */ SavedFrame*
 Debugger::getObjectAllocationSite(JSObject& obj)
 {
     JSObject* metadata = GetObjectMetadata(&obj);
     if (!metadata)
         return nullptr;
 
     MOZ_ASSERT(!metadata->is<WrapperObject>());
     return SavedFrame::isSavedFrameAndNotProto(*metadata)
-        ? metadata
+        ? &metadata->as<SavedFrame>()
         : nullptr;
 }
 
 static bool
 DebuggerObject_getAllocationSite(JSContext* cx, unsigned argc, Value* vp)
 {
     THIS_DEBUGOBJECT_REFERENT(cx, argc, vp, "get allocationSite", args, obj);
 

--- a/js/src/vm/Debugger.h
+++ b/js/src/vm/Debugger.h
@@ -282,17 +282,17 @@ class Debugger : private mozilla::Linked
         return trackingTenurePromotions;
     }
 
     bool isEnabled() const {
         return enabled;
     }
 
     void logTenurePromotion(JSRuntime* rt, JSObject& obj, double when);
-    static JSObject* getObjectAllocationSite(JSObject& obj);
+    static SavedFrame* getObjectAllocationSite(JSObject& obj);
 
     struct TenurePromotionsLogEntry : public JS::Traceable
     {
         TenurePromotionsLogEntry(JSRuntime* rt, JSObject& obj, double when);
 
         const char* className;
         double when;
         RelocatablePtrObject frame;