--- a/lib/prefs.py
+++ b/lib/prefs.py
@@ -1,3 +1,6 @@
+import gi
+gi.require_version("Gtk", "3.0")
+gi.require_version('GConf', '2.0')
 from gi.repository import Gtk
 from gi.repository import GConf
 import inspect

--- a/lib/gui.py
+++ b/lib/gui.py
@@ -1,6 +1,9 @@
 # -*- coding: utf-8 -*-
 
 import os, sys
+import gi
+gi.require_version('GtkSource', '3.0')
+gi.require_version("Gtk", "3.0")
 from gi.repository import GObject, Gio, Gtk, Gdk, GdkPixbuf, GLib
 import tempfile
 from gi.repository import Pango
@@ -2801,7 +2804,7 @@
         for stock_name, file in self.icons.iteritems():
             factory = Gtk.IconFactory()
             pixbuf = GdkPixbuf.Pixbuf.new_from_file(file)
-            iconset = Gtk.IconSet(pixbuf)
+            iconset = Gtk.IconSet.new_from_pixbuf(pixbuf)
             factory.add(stock_name, iconset)
             factory.add_default()