diff --git a/src/util/memory_manager.h b/src/util/memory_manager.h
index a52e3e3bd..1d9a604af 100644
--- a/src/util/memory_manager.h
+++ b/src/util/memory_manager.h
@@ -75,7 +75,7 @@ public:
 };
 
 
-#if _DEBUG
+#if Z3DEBUG
 
 #define alloc(T,...) new (memory::allocate(__FILE__,__LINE__,#T, sizeof(T))) T(__VA_ARGS__)
 #define dealloc(_ptr_) deallocf(__FILE__,__LINE__,_ptr_)