--- a/js/src/jsfriendapi.cpp
+++ b/js/src/jsfriendapi.cpp
@@ -1413,8 +1413,14 @@ js::IsWindowProxy(JSObject* obj)
     return obj->getClass() == obj->runtimeFromAnyThread()->maybeWindowProxyClass();
 }
 
 JS_FRIEND_API(bool)
 js::detail::IsWindowSlow(JSObject* obj)
 {
     return obj->as<GlobalObject>().maybeWindowProxy();
 }
+
+JS_FRIEND_API(bool)
+js::AllowGCBarriers(JSContext* cx)
+{
+    return cx->allowGCBarriers();
+}

--- a/js/src/jsfriendapi.h
+++ b/js/src/jsfriendapi.h
@@ -2899,16 +2899,19 @@ ToWindowProxyIfWindow(JSObject* obj);
 /**
  * If `obj` is a WindowProxy, get its associated Window (the compartment's
  * global), else return `obj`. This function is infallible and never returns
  * nullptr.
  */
 extern JS_FRIEND_API(JSObject*)
 ToWindowIfWindowProxy(JSObject* obj);
 
+JS_FRIEND_API(bool)
+AllowGCBarriers(JSContext* cx);
+
 } /* namespace js */
 
 class NativeProfiler
 {
   public:
     virtual ~NativeProfiler() {};
     virtual void sampleNative(void* addr, uint32_t size) = 0;
     virtual void removeNative(void* addr) = 0;