--- OLD/xc/lib/Xext/XTestExt1.c	Thu Jan  1 00:00:00 1970
+++ NEW/xc/lib/Xext/XTestExt1.c	Thu Jan  1 00:00:00 1970
@@ -52,6 +52,8 @@
  * include files
  *****************************************************************************/
 
+#include <stdio.h>
+
 #define NEED_REPLIES
 #define NEED_EVENTS