diff --git a/trick_source/sim_services/MemoryManager/MemoryManager_ref_name.cpp b/trick_source/sim_services/MemoryManager/MemoryManager_ref_name.cpp
index deef219f..a56a96f7 100644
--- a/trick_source/sim_services/MemoryManager/MemoryManager_ref_name.cpp
+++ b/trick_source/sim_services/MemoryManager/MemoryManager_ref_name.cpp
@@ -12,6 +12,7 @@
 #include "trick/reference.h"
 #include "trick/parameter_types.h"
 #include "trick/mm_error.h"
+#include <stdlib.h> 
 
 //FIXME TODO make a error file
 /////// MM_NO_ERROR 0