diff --git a/packages/core/integration-tests/test/integration/webextension-mv3/manifest.json b/packages/core/integration-tests/test/integration/webextension-mv3/manifest.json
index b8ff5f08993..08398794f2c 100644
--- a/packages/core/integration-tests/test/integration/webextension-mv3/manifest.json
+++ b/packages/core/integration-tests/test/integration/webextension-mv3/manifest.json
@@ -4,7 +4,9 @@
   "version": "0.1",
   "manifest_version": 3,
   "background": {
-    "service_worker": "background.js"
+    "service_worker": "background.js",
+    "type": "module",
+    "scripts": [ "background.js" ]
   },
   "permissions": [
     "scripting",
diff --git a/packages/core/integration-tests/test/webextension.js b/packages/core/integration-tests/test/webextension.js
index f31629fffb7..2e2a681fbfc 100644
--- a/packages/core/integration-tests/test/webextension.js
+++ b/packages/core/integration-tests/test/webextension.js
@@ -111,6 +111,7 @@ describe('webextension', function () {
         assets: ['manifest.json'],
       },
       {assets: ['background.js']},
+      {assets: ['background.js']},
       {assets: ['popup.html']},
       {assets: ['popup.css']},
       {assets: ['popup.js', 'esmodule-helpers.js', 'bundle-url.js']},
diff --git a/packages/transformers/webextension/src/WebExtensionTransformer.js b/packages/transformers/webextension/src/WebExtensionTransformer.js
index 51cbe6a0ef7..3ee647fe8a9 100644
--- a/packages/transformers/webextension/src/WebExtensionTransformer.js
+++ b/packages/transformers/webextension/src/WebExtensionTransformer.js
@@ -273,7 +273,8 @@ async function collectDependencies(
         ...getJSONSourceLocation(ptrs['/background/page'], 'value'),
       },
     });
-  } else if (program.background?.service_worker) {
+  }
+  if (program.background?.service_worker) {
     program.background.service_worker = asset.addURLDependency(
       program.background.service_worker,
       {
diff --git a/packages/transformers/webextension/src/schema.js b/packages/transformers/webextension/src/schema.js
index 20f6dc6ca08..3f38853ef8b 100644
--- a/packages/transformers/webextension/src/schema.js
+++ b/packages/transformers/webextension/src/schema.js
@@ -473,6 +473,10 @@ export const MV3Schema = ({
               type: 'string',
               enum: ['classic', 'module'],
             },
+            // to support both Chrome and Firefox
+            scripts: arrStr,
+            page: string,
+            persistent: boolean,
           },
           additionalProperties: false,
           required: ['service_worker'],