diff --git a/TileGenerator.cpp b/TileGenerator.cpp
index befab15..3f72b7e 100644
--- a/TileGenerator.cpp
+++ b/TileGenerator.cpp
@@ -1,4 +1,5 @@
 #include <cstdio>
+#include <cstdlib>
 #include <climits>
 #include <fstream>
 #include <iostream>