missing header

Index: src/Core/OOPriorityQueue.m
--- src/Core/OOPriorityQueue.m.orig
+++ src/Core/OOPriorityQueue.m
@@ -29,6 +29,9 @@ SOFTWARE.
 #import "OOPriorityQueue.h"
 #import "OOFunctionAttributes.h"
 
+#include <assert.h>
+
+
 
 /*	Capacity grows by 50% each time. kMinCapacity must be at least 2 or Bad
 	Things will happen. Some examples of growth patterns based on kMinCapacity:
