diff --git a/mkfiles.pl b/mkfiles.pl
index 9466ffec..8155c901 100755
--- a/mkfiles.pl
+++ b/mkfiles.pl
@@ -928,10 +928,10 @@ if (defined $makefiles{'gtk'}) {
     "KRB5CONFIG=krb5-config\n".
     "# You can manually set this to `gtk-config' or `pkg-config gtk+-1.2'\n".
     "# (depending on what works on your system) if you want to enforce\n".
-    "# building with GTK 1.2, or you can set it to `pkg-config gtk+-2.0'\n".
+    "# building with GTK 1.2, or you can set it to `pkg-config gtk+-2.0 x11'\n".
     "# if you want to enforce 2.0. The default is to try 2.0 and fall back\n".
     "# to 1.2 if it isn't found.\n".
-    "GTK_CONFIG = sh -c 'pkg-config gtk+-2.0 \$\$0 2>/dev/null || gtk-config \$\$0'\n".
+    "GTK_CONFIG = sh -c 'pkg-config gtk+-2.0 x11 \$\$0 2>/dev/null || gtk-config \$\$0'\n".
     "\n".
     "-include Makefile.local\n".
     "\n".
diff --git a/unix/configure.ac b/unix/configure.ac
index dcbc1535..d84d61e1 100644
--- a/unix/configure.ac
+++ b/unix/configure.ac
@@ -51,6 +51,8 @@ if test "$with_gssapi" != "no"; then
   AC_SEARCH_LIBS([gss_init_sec_context], [gssapi gssapi_krb5 gss])
 fi
 
+AC_CHECK_LIB(X11, XOpenDisplay)
+
 AC_CHECK_FUNCS([getaddrinfo ptsname setresuid strsignal updwtmpx])
 
 AC_OUTPUT