diff --git a/mobile/chrome/content/bindings/browser.xml b/mobile/chrome/content/bindings/browser.xml
index cb68b93b6781..eb92194dfb04 100644
--- a/mobile/chrome/content/bindings/browser.xml
+++ b/mobile/chrome/content/bindings/browser.xml
@@ -358,7 +358,9 @@
             // (as opposed to one of its iframes).
             if (this.feeds && aMessage.target == this)
               this.feeds = null;
-            this.scale = 1;
+
+            if (aMessage.windowId == this.contentWindowId)
+              this.scale = 1;
          ]]>
         </body>
       </method>