diff --git a/dom/workers/ServiceWorkerManager.cpp b/dom/workers/ServiceWorkerManager.cpp
index 6d5f00f2f0f7..4b037843b541 100644
--- a/dom/workers/ServiceWorkerManager.cpp
+++ b/dom/workers/ServiceWorkerManager.cpp
@@ -1304,9 +1304,16 @@ ServiceWorkerManager::WorkerIsIdle(ServiceWorkerInfo* aWorker)
     return;
   }
 
-  if (reg->GetActive() == aWorker) {
-    reg->TryToActivateAsync();
+  if (reg->GetActive() != aWorker) {
+    return;
   }
+
+  if (!reg->IsControllingDocuments() && reg->mPendingUninstall) {
+    RemoveRegistration(reg);
+    return;
+  }
+
+  reg->TryToActivateAsync();
 }
 
 already_AddRefed<ServiceWorkerJobQueue>
@@ -2001,7 +2008,7 @@ void
 ServiceWorkerManager::StopControllingADocument(ServiceWorkerRegistrationInfo* aRegistration)
 {
   aRegistration->StopControllingADocument();
-  if (aRegistration->IsControllingDocuments()) {
+  if (aRegistration->IsControllingDocuments() || !aRegistration->IsIdle()) {
     return;
   }
 
diff --git a/dom/workers/ServiceWorkerUnregisterJob.cpp b/dom/workers/ServiceWorkerUnregisterJob.cpp
index cc19a6ec0264..b56d0b761eec 100644
--- a/dom/workers/ServiceWorkerUnregisterJob.cpp
+++ b/dom/workers/ServiceWorkerUnregisterJob.cpp
@@ -139,7 +139,7 @@ ServiceWorkerUnregisterJob::Unregister()
   InvokeResultCallbacks(NS_OK);
 
   // "If no service worker client is using registration..."
-  if (!registration->IsControllingDocuments()) {
+  if (!registration->IsControllingDocuments() && registration->IsIdle()) {
     // "Invoke [[Clear Registration]]..."
     swm->RemoveRegistration(registration);
   }