@@ -18,14 +18,10 @@
 
 /**
  * \brief An mutable unordered set of unique objects.
  */
 @interface OFMutableSet: OFSet
-{
-	unsigned long mutations;
-}
-
 /**
  * \brief Adds the specified object to the set.
  *
  * \param object The object to add to the set
  */
@@ -63,5 +59,8 @@
 /**
  * \brief Converts the mutable set to an immutable set.
  */
 - (void)makeImmutable;
 @end
+
+@interface OFMutableSet_placeholder: OFMutableSet
+@end