1 files changed, 3 insertions, 1 deletions
diff --git a/toolkit/components/extensions/parent/ext-backgroundPage.js b/toolkit/components/extensions/parent/ext-backgroundPage.js
index 725be65122..568d049b9d 100644
--- a/toolkit/components/extensions/parent/ext-backgroundPage.js
+++ b/toolkit/components/extensions/parent/ext-backgroundPage.js
@@ -264,7 +264,9 @@ this.backgroundPage = class extends ExtensionAPI {
     let { manifest } = extension;
     extension.backgroundState = BACKGROUND_STATE.STARTING;
 
-    this.isWorker = Boolean(manifest.background.service_worker);
+    this.isWorker =
+      !!manifest.background.service_worker &&
+      WebExtensionPolicy.backgroundServiceWorkerEnabled;
 
     let BackgroundClass = this.isWorker ? BackgroundWorker : BackgroundPage;