diff --git a/main.cpp b/main.cpp
index ef1197f..2f3969d 100644
--- a/main.cpp
+++ b/main.cpp
@@ -1,6 +1,7 @@
 #include "input_parsing.h"
 
 #include <iostream>
+#include <stdlib.h>
 
 int main(int argc, char *argv[])
 {