--- a/configure.in
+++ b/configure.in
@@ -14,7 +14,6 @@
 	echo
 	exit 1)
 
-LDFLAGS=`gtk-config --cflags`
+PKG_CHECK_MODULES(LIBX11, x11,[LIBS="$LIBS $LIBX11_LIBS";INCLUDES="$INCLUDES $LIBX11_CFLAGS"],[exit 1])
 
-AC_SUBST(LDFLAGS)
 AC_OUTPUT(Makefile)