diff --git a/Foundation/CPString.j b/Foundation/CPString.j
index 8f3b03898..6c6ed9acf 100644
--- a/Foundation/CPString.j
+++ b/Foundation/CPString.j
@@ -527,13 +527,13 @@ var CPStringRegexSpecialCharacters = [
 - (unsigned)UID
 {
     var hash = CPStringHashes.valueForKey(self);
-    
+
     if (!hash) 
     {
         hash = _objj_generateObjectHash();
-        CPStringHashes.setValueForKey(hash, self);
+        CPStringHashes.setValueForKey(self, hash);
     }
-    
+
     return hash;
 }