diff --git a/platform/mv3/extension/js/background.js b/platform/mv3/extension/js/background.js
index d266cccdd..e025d1317 100644
--- a/platform/mv3/extension/js/background.js
+++ b/platform/mv3/extension/js/background.js
@@ -680,7 +680,7 @@ async function startSession() {
     const shouldInject = isNewVersion || permissionsUpdated ||
         isSideloaded && rulesetConfig.developerMode;
     if ( shouldInject ) {
-        registerInjectables();
+        await registerInjectables();
     }
 
     // Cosmetic filtering-related content scripts cache fitlering data in
@@ -730,6 +730,11 @@ async function start() {
         scrmgr.onWakeupRun();
     }
 
+    const scripts = await scrmgr.getRegisteredContentScripts();
+    if ( scripts.length === 0 ) {
+        registerInjectables();
+    }
+
     toggleDeveloperMode(rulesetConfig.developerMode);
 }