diff --git a/docs/js/metro/metro-button-set.js b/docs/js/metro/metro-button-set.js
index <HASH>..<HASH> 100644
--- a/docs/js/metro/metro-button-set.js
+++ b/docs/js/metro/metro-button-set.js
@@ -28,7 +28,7 @@
                     btn.toggleClass("active");
 
                     that.options.click(btn, btn.hasClass("active"));
-                    that._trigger("click", event, {button: btn, on: (btn.hasClass("active"))});
+                    that._trigger("click", null, {button: btn, on: (btn.hasClass("active"))});
                 });
             });
         },
@@ -72,7 +72,7 @@
                     btn.addClass("active");
 
                     that.options.click(btn, btn.hasClass("active"));
-                    that._trigger("click", event, {button: btn, on: (btn.hasClass("active"))});
+                    that._trigger("click", null, {button: btn, on: (btn.hasClass("active"))});
                 });
             });
         },
Major compatibility fix for Firefox and IE with buttons

Fixed a bug, where buttongroup and -set events were not called properly
with Firefox and IE.