--- a/dom/base/nsScriptLoader.cpp
+++ b/dom/base/nsScriptLoader.cpp
@@ -2216,18 +2216,23 @@ void
 nsScriptLoader::ProcessPendingRequestsAsync()
 {
   if (mParserBlockingRequest ||
       !mXSLTRequests.isEmpty() ||
       !mLoadedAsyncRequests.isEmpty() ||
       !mNonAsyncExternalScriptInsertedRequests.isEmpty() ||
       !mDeferRequests.isEmpty() ||
       !mPendingChildLoaders.IsEmpty()) {
-    NS_DispatchToCurrentThread(NewRunnableMethod(this,
-                                                 &nsScriptLoader::ProcessPendingRequests));
+    nsCOMPtr<nsIRunnable> task = NewRunnableMethod(this,
+                                                   &nsScriptLoader::ProcessPendingRequests);
+    if (mDocument) {
+      mDocument->Dispatch("ScriptLoader", TaskCategory::Other, task.forget());
+    } else {
+      NS_DispatchToCurrentThread(task.forget());
+    }
   }
 }
 
 void
 nsScriptLoader::ProcessPendingRequests()
 {
   RefPtr<nsScriptLoadRequest> request;