diff --git a/tutorial/Gfx.pmod b/tutorial/Gfx.pmod
index 24d70ecac15463703ab57ec982c5ce9a57900337..65bc21d03fbb4ed21c6984a64c9ec780fbd0a90d 100644
--- a/tutorial/Gfx.pmod
+++ b/tutorial/Gfx.pmod
@@ -46,6 +46,7 @@ string cached_write(string data, string ext)
     }
 
   image_num++;
+  mkdir("gfx");
   string filename="gfx/i"+image_num+"."+ext;
   rm(filename);
   werror("Writing "+filename+".\n");