diff --git a/lib/jquery.waypoints.js b/lib/jquery.waypoints.js
index d70b245..ba42200 100644
--- a/lib/jquery.waypoints.js
+++ b/lib/jquery.waypoints.js
@@ -633,7 +633,7 @@ https://github.com/imakewebthings/waypoints/blob/master/licenses.txt
       var waypoints = []
       var overrides = arguments[0]
 
-      if (framework.isFunction(arguments[0])) {
+      if (typeof arguments[0] === "function"){
         overrides = framework.extend({}, arguments[1])
         overrides.handler = arguments[0]
       }
@@ -659,4 +659,4 @@ https://github.com/imakewebthings/waypoints/blob/master/licenses.txt
     window.Zepto.fn.waypoint = createExtension(window.Zepto)
   }
 }())
-;
\ No newline at end of file
+;