diff --git a/mobile/android/chrome/content/browser.js b/mobile/android/chrome/content/browser.js
index 8e111990bf6..5df8947c827 100644
--- a/mobile/android/chrome/content/browser.js
+++ b/mobile/android/chrome/content/browser.js
@@ -1508,6 +1508,8 @@ Tab.prototype = {
     this.browser.removeEventListener("pagehide", this, true);
     this.browser.removeEventListener("pageshow", this, true);
 
+    Services.obs.removeObserver(this, "document-shown");
+
     // Make sure the previously selected panel remains selected. The selected panel of a deck is
     // not stable when panels are removed.
     let selectedPanel = BrowserApp.deck.selectedPanel;