diff --git a/Source/IndexedCollection.m b/Source/IndexedCollection.m
index c173e15ab..9ab067335 100644
--- a/Source/IndexedCollection.m
+++ b/Source/IndexedCollection.m
@@ -327,7 +327,7 @@
 
 + (void) initialize
 {
-  if (self == [KeyedCollection class])
+  if (self == [IndexedCollection class])
     class_add_behavior(self, [Collection class]);
 }