diff --git a/lib/cmd.c b/lib/cmd.c
index 8496a96..832d83f 100644
--- a/lib/cmd.c
+++ b/lib/cmd.c
@@ -32,6 +32,7 @@
 #include <math.h>
 #include <sys/time.h>
 #include <string.h>
+#include <stdlib.h>
 
 #include <libinternal.h>