--- screen-4.0.3.orig/configure.in
+++ screen-4.0.3/configure.in
@@ -1206,7 +1206,7 @@
 rm -f /tmp/conftest*
 
 AC_MSG_CHECKING(for vsprintf)
-AC_TRY_LINK(,[vsprintf(0,0,0);], AC_MSG_RESULT(yes);AC_DEFINE(USEVARARGS), AC_MSG_RESULT(no))
+AC_TRY_LINK([#include <stdarg.h>],[va_list valist; vsprintf(0,0,valist);], AC_MSG_RESULT(yes);AC_DEFINE(USEVARARGS), AC_MSG_RESULT(no))
 
 AC_HEADER_DIRENT