diff --git a/background/background.js b/background/background.js
index a699fdfa..48122647 100644
--- a/background/background.js
+++ b/background/background.js
@@ -239,6 +239,7 @@ window.addEventListener('storageReady', function _() {
   }
 
   const injectCS = (cs, tabId) => {
+    if (chrome.runtime.lastError) return;
     chrome.tabs.executeScript(tabId, {
       file: cs.js[0],
       runAt: cs.run_at,