diff --git a/src/utils.cpp b/src/utils.cpp
index bbda22f24c..34e6e6fae6 100644
--- a/src/utils.cpp
+++ b/src/utils.cpp
@@ -13,6 +13,7 @@
 
 #include <mpi.h>
 #include <cstring>
+#include <cstdlib>
 #include "utils.h"
 #include "lammps.h"
 #include "error.h"