diff --git a/tests/mem.c b/tests/mem.c
index 0faa781f43..cc104cbb92 100644
--- a/tests/mem.c
+++ b/tests/mem.c
@@ -1,4 +1,5 @@
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 
 int main(int argc, char ** argv) {