diff --git a/gloo/common/utils.cc b/gloo/common/utils.cc
index ab075776c..73ec1193a 100644
--- a/gloo/common/utils.cc
+++ b/gloo/common/utils.cc
@@ -12,6 +12,7 @@
 #include <winsock2.h>
 #else
 #include <unistd.h>
+#include <cstdlib>
 #endif
 
 #include "gloo/common/utils.h"