Index: configure.ac
===================================================================
--- configure.ac	(revision 126)
+++ configure.ac	(working copy)
@@ -37,13 +37,24 @@
      AC_MSG_ERROR([Could not find pthread_join in -lpthread.]))
 AC_CHECK_HEADERS([pthread.h])
 
-PKG_CHECK_MODULES(X11, x11)
+PKG_CHECK_MODULES(X11, x11, [have_x11=yes], [have_x11=no])
+if test x$have_x11 = xno
+then
+   AC_PATH_X
+   if test x"$x_includes" != x"NONE" && test -n "$x_includes" ; then
+     X11_CFLAGS=-I`echo $x_includes | sed -e "s/:/ -I/g"`
+   fi
+   if test x"$x_libraries" != x"NONE" && test -n "$x_libraries" ; then
+     X11_LIBS=-L`echo $x_libraries | sed -e "s/:/ -L/g"`
+   fi
+   X11_LIBS="$X11_LIBS -lX11"
+fi
 
 if test "x$GCC" = "xyes"; then
         GCC_FLAGS="-g -Wall"
 fi
 
-VINCENT_CFLAGS="$X11_FLAGS $PTHREAD_CFLAGS"
+VINCENT_CFLAGS="$X11_CFLAGS $PTHREAD_CFLAGS"
 VINCENT_LIBS="$X11_LIBS $PTHREAD_LIBS"
 
 AC_SUBST(VINCENT_CFLAGS)