diff --git a/lib/sinon/util/fake_timers.js b/lib/sinon/util/fake_timers.js
index ccb9ce98b..1eedc1046 100644
--- a/lib/sinon/util/fake_timers.js
+++ b/lib/sinon/util/fake_timers.js
@@ -324,7 +324,7 @@ if (typeof sinon == "undefined") {
 
         return clock;
     };
-}(typeof global != "undefined" ? global : this));
+}(typeof global != "undefined" && typeof global !== "function" ? global : this));
 
 sinon.timers = {
     setTimeout: setTimeout,