diff --git a/drop_privs.c b/drop_privs.c
index 9f769e5..8183f6c 100644
--- a/drop_privs.c
+++ b/drop_privs.c
@@ -35,6 +35,7 @@
 #include <grp.h>
 #include <errno.h>
 #include <string.h>
+#include <stdlib.h>
 
 #include "util.h"