diff --git a/source/gl_rsurf.c b/source/gl_rsurf.c
index 0429e30..fe7e0a0 100644
--- a/source/gl_rsurf.c
+++ b/source/gl_rsurf.c
@@ -26,8 +26,9 @@
 	$Id$
 */
 // r_surf.c: surface-related refresh code
-#include <math.h>
 #include <stdio.h>
+#include <string.h>
+#include <math.h>
 
 #include "bothdefs.h"   // needed by: common.h, net.h, client.h