Index: gui-gtk-3.0/gui_stuff.c
===================================================================
--- gui-gtk-3.0/gui_stuff.c	(revision 21542)
+++ gui-gtk-3.0/gui_stuff.c	(working copy)
@@ -1032,7 +1032,22 @@
               "widget \"Freeciv*.%s\" style \"ext-%s\"",
               font_name, font_value, font_name, font_name);
 
+  GtkCssProvider *provider;
+  fc_snprintf(str, sizeof(str),
+              "#Freeciv #%s {\n"
+              "  font: %s\n"
+              "}\n",
+              font_name, font_value);
+
   gtk_rc_parse_string(str);
+
+  provider = gtk_css_provider_new();
+  gtk_css_provider_load_from_data (GTK_CSS_PROVIDER(provider),
+    str, -1, NULL);
+  gtk_style_context_add_provider_for_screen(
+    gtk_widget_get_screen(toplevel),
+    GTK_STYLE_PROVIDER(provider), GTK_STYLE_PROVIDER_PRIORITY_APPLICATION);
+
 }
 
 /****************************************************************************