--- xfce4-settings-4.10.0.orig/dialogs/appearance-settings/appearance-install-theme
+++ xfce4-settings-4.10.0/dialogs/appearance-settings/appearance-install-theme
@@ -140,7 +140,7 @@ if test "$retval" -eq 0; then
     detectthemes "gtk-2.0/gtkrc"
 
     # install gtk-3.0 themes
-    detectthemes "gtk-3.0/gtkrc"
+    detectthemes "gtk-3.0/gtk.css"
 
     # install xfwm4 themes
     detectthemes "xfwm4/themerc"