diff --git a/silly.c b/silly.c
index 57d07e8..102156a 100644
--- a/silly.c
+++ b/silly.c
@@ -13,6 +13,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <math.h>
+#include <string.h>
 
 #ifndef WIN32
 #include <GL/gl.h>