diff --git a/xpcom/base/CycleCollectedJSRuntime.h b/xpcom/base/CycleCollectedJSRuntime.h
index 7937d935cff..4d306f4a282 100644
--- a/xpcom/base/CycleCollectedJSRuntime.h
+++ b/xpcom/base/CycleCollectedJSRuntime.h
@@ -215,7 +215,9 @@ private:
   void TraceNativeGrayRoots(JSTracer* aTracer);
 
   void AfterProcessMicrotask(uint32_t aRecursionDepth);
+public:
   void ProcessStableStateQueue();
+private:
   void ProcessMetastableStateQueue(uint32_t aRecursionDepth);
 
 public:
diff --git a/xpcom/base/nsCycleCollector.cpp b/xpcom/base/nsCycleCollector.cpp
index 82e0b412b31..374e5daaab9 100644
--- a/xpcom/base/nsCycleCollector.cpp
+++ b/xpcom/base/nsCycleCollector.cpp
@@ -4166,6 +4166,11 @@ nsCycleCollector_shutdown()
 
     data->mCollector->Shutdown();
     data->mCollector = nullptr;
+    if (data->mRuntime) {
+      // Run any remaining tasks that may have been enqueued via
+      // RunInStableState during the final cycle collection.
+      data->mRuntime->ProcessStableStateQueue();
+    }
     if (!data->mRuntime) {
       delete data;
       sCollectorData.set(nullptr);