2 files changed, 8 insertions, 3 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;
 
diff --git a/toolkit/components/extensions/parent/ext-runtime.js b/toolkit/components/extensions/parent/ext-runtime.js
index cd18e0f0aa..2122e8faed 100644
--- a/toolkit/components/extensions/parent/ext-runtime.js
+++ b/toolkit/components/extensions/parent/ext-runtime.js
@@ -237,9 +237,12 @@ this.runtime = class extends ExtensionAPIPersistent {
         },
 
         async internalWakeupBackground() {
+          const { background } = extension.manifest;
           if (
-            extension.manifest.background &&
-            !extension.manifest.background.service_worker &&
+            background &&
+            (background.page || background.scripts) &&
+            // Note: if background.service_worker is specified, it takes
+            // precedence over page/scripts, and persistentBackground is false.
             !extension.persistentBackground
           ) {
             await extension.wakeupBackground();