diff --git a/util/env_chroot.cc b/util/env_chroot.cc
index 116747dc0..37939821e 100644
--- a/util/env_chroot.cc
+++ b/util/env_chroot.cc
@@ -8,6 +8,7 @@
 #include "util/env_chroot.h"
 
 #include <errno.h>
+#include <stdlib.h>
 #include <string.h>
 #include <unistd.h>