diff --git a/src/contentScript.js b/src/contentScript.js
index 1baca88d..8d90a1ed 100644
--- a/src/contentScript.js
+++ b/src/contentScript.js
@@ -528,6 +528,7 @@ function loadEventListener() {
 
   //detect tab switching to reset env
   addEventHandler("blur", resetTooltipStatus);
+  addEventHandler("beforeunload", killAutoReader);
 }
 
 function handleMousemove(e) {