diff -up ./configure.ac.0020 ./configure.ac
--- ./configure.ac.0020	2012-08-30 18:03:56.000000000 +0000
+++ ./configure.ac	2013-04-01 13:25:01.167359525 +0000
@@ -14,15 +14,24 @@ GOBJECT_INTROSPECTION_CHECK(0.9.5)
 GNOME_COMPILE_WARNINGS(maximum)
 
 dnl ###########################################################################
+dnl Standard headers
+dnl ###########################################################################
+
+AC_CHECK_HEADERS([stdlib.h])
+
+dnl ###########################################################################
 dnl Dependencies
 dnl ###########################################################################
 
-PKG_CHECK_MODULES(GREETER, [
-    gtk+-3.0
-    x11
-    liblightdm-gobject-1
-    gmodule-export-2.0
-])
+AC_ARG_WITH([gtk2], AS_HELP_STRING([--with-gtk2], [Use gtk+-2.0 instead of gtk+-3.0]))
+
+AS_IF([test "x$with_gtk2" = "xyes"],
+      [PKG_CHECK_MODULES([GTK], [gtk+-2.0], [have_gtk2=yes])],
+      [PKG_CHECK_MODULES([GTK], [gtk+-3.0])])
+
+PKG_CHECK_MODULES([GMODULE], [gmodule-export-2.0])
+PKG_CHECK_MODULES([LIGHTDMGOBJECT], [liblightdm-gobject-1 >= 1.3.5])
+PKG_CHECK_MODULES([LIBX11], [x11])
 
 dnl ###########################################################################
 dnl Internationalization
diff -up ./data/greeter.ui.0020 ./data/greeter.ui
--- ./data/greeter.ui.0020	2013-04-01 13:29:37.159436699 +0000
+++ ./data/greeter.ui	2013-04-01 13:29:42.987177375 +0000
@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <interface>
-  <requires lib="gtk+" version="3.0"/>
   <object class="GtkListStore" id="language_liststore">
     <columns>
       <!-- column-name label -->
diff -up ./src/lightdm-gtk-greeter.c.0020 ./src/lightdm-gtk-greeter.c
--- ./src/lightdm-gtk-greeter.c.0020	2013-04-01 13:25:01.165359271 +0000
+++ ./src/lightdm-gtk-greeter.c	2013-04-01 13:25:01.167359525 +0000
@@ -736,7 +736,11 @@ main (int argc, char **argv)
     GtkWidget *menuitem, *hbox, *image;
     gchar *value, *state_dir;
     GdkPixbuf *background_pixbuf = NULL;
+    #if GTK_CHECK_VERSION (3, 0, 0)
     GdkRGBA background_color;
+    #else
+    GdkColor background_color;
+    #endif
     gint i;
     GError *error = NULL;
 
@@ -785,7 +789,11 @@ main (int argc, char **argv)
     value = g_key_file_get_value (config, "greeter", "background", NULL);
     if (!value)
         value = g_strdup ("#000000");
+    #if GTK_CHECK_VERSION (3, 0, 0)
     if (!gdk_rgba_parse (&background_color, value))
+    #else
+    if (!gdk_color_parse (value, &background_color))
+    #endif
     {
         gchar *path;
         GError *error = NULL;
@@ -831,7 +839,11 @@ main (int argc, char **argv)
                 g_object_unref (pixbuf);
             }
             else
+                #if GTK_CHECK_VERSION (3, 0, 0)
                 gdk_cairo_set_source_rgba (c, &background_color);
+                #else
+                gdk_cairo_set_source_color (c, &background_color);
+                #endif
             cairo_paint (c);
         }
 
@@ -939,7 +951,11 @@ main (int argc, char **argv)
 
     /* Glade can't handle custom menuitems, so set them up manually */
     menuitem = GTK_WIDGET (gtk_builder_get_object (builder, "power_menuitem"));
+    #if GTK_CHECK_VERSION (3, 0, 0)
     hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
+    #else
+    hbox = gtk_hbox_new (FALSE, 0);
+    #endif
     gtk_widget_show (hbox);
     gtk_container_add (GTK_CONTAINER (menuitem), hbox);
     image = gtk_image_new_from_icon_name ("system-shutdown", GTK_ICON_SIZE_MENU);
@@ -947,7 +963,11 @@ main (int argc, char **argv)
     gtk_box_pack_start (GTK_BOX (hbox), image, FALSE, TRUE, 0);
 
     menuitem = GTK_WIDGET (gtk_builder_get_object (builder, "a11y_menuitem"));
+    #if GTK_CHECK_VERSION (3, 0, 0)
     hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
+    #else
+    hbox = gtk_hbox_new (FALSE, 0);
+    #endif
     gtk_widget_show (hbox);
     gtk_container_add (GTK_CONTAINER (menuitem), hbox);
     image = gtk_image_new_from_icon_name ("preferences-desktop-accessibility", GTK_ICON_SIZE_MENU);