diff --git a/browser/components/preferences/permissions.js b/browser/components/preferences/permissions.js
index dc6e4b42fafe..995123b06570 100644
--- a/browser/components/preferences/permissions.js
+++ b/browser/components/preferences/permissions.js
@@ -236,10 +236,17 @@ var gPermissionManager = {
         }
         this._tree.treeBoxObject.invalidate();
       }
-      // No UI other than this window causes this method to be sent a "deleted"
-      // notification, so we don't need to implement it since Delete is handled
-      // directly by the Permission Removal handlers. If that ever changes, those
-      // implementations will have to move into here. 
+      else if (aData == "deleted") {
+        for (var i = 0; i < this._permissions.length; i++) {
+          if (this._permissions[i].host == permission.host) {
+            this._permissions.splice(i, 1);
+            this._view._rowCount--;
+            this._tree.treeBoxObject.rowCountChanged(this._view.rowCount - 1, -1);
+            this._tree.treeBoxObject.invalidate();
+            break;
+          }
+        }
+      }
     }
   },
   
diff --git a/browser/components/preferences/tests/browser_cookies_exceptions.js b/browser/components/preferences/tests/browser_cookies_exceptions.js
index 9f5463334c3e..c47c7fc3dbbf 100644
--- a/browser/components/preferences/tests/browser_cookies_exceptions.js
+++ b/browser/components/preferences/tests/browser_cookies_exceptions.js
@@ -114,6 +114,17 @@ function windowLoad(event, win, dialog) {
         pm.remove("test.com", "popup");
       },
     },
+    {
+      test: function() {
+        url.value = "test.com";
+        btnAllow.doCommand();
+        pm.remove("test.com", "cookie");
+        is(tree.view.rowCount, 0, "display should update when cookie permission is deleted");
+      },
+      observances: [{ type: "cookie", host: "test.com", data: "added",
+                      capability: allow },
+                    { type: "cookie", host: "test.com", data: "deleted" }]
+    },
   ];
 
   let permObserver = {