diff --git a/src/OSD/OSD_MAllocHook.cxx b/src/OSD/OSD_MAllocHook.cxx
index 485a44850f..1b4594b5cb 100755
--- a/src/OSD/OSD_MAllocHook.cxx
+++ b/src/OSD/OSD_MAllocHook.cxx
@@ -14,6 +14,7 @@
 
 #include <set>
 #include <map>
+#include <cstdlib>
 
 #ifndef SIZE_MAX
 #define SIZE_MAX UINT_MAX