diff --git a/src/attacks/attacks.c b/src/attacks/attacks.c
index e511e70..e75f660 100644
--- a/src/attacks/attacks.c
+++ b/src/attacks/attacks.c
@@ -1,3 +1,4 @@
+#include <stdlib.h>
 #include <string.h>
 
 #include "attacks.h"
diff --git a/src/attacks/dummy.c b/src/attacks/dummy.c
index 8fe5ba8..ae7aae2 100644
--- a/src/attacks/dummy.c
+++ b/src/attacks/dummy.c
@@ -1,4 +1,5 @@
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 
 #include "dummy.h"