diff --git a/deluge/ui/gtk3/addtorrentdialog.py b/deluge/ui/gtk3/addtorrentdialog.py
index aa427e80c..d6fd54116 100644
--- a/deluge/ui/gtk3/addtorrentdialog.py
+++ b/deluge/ui/gtk3/addtorrentdialog.py
@@ -802,7 +802,7 @@ class AddTorrentDialog(component.Component):
         dialog.show_all()
         response = dialog.run()
         infohash = entry.get_text().strip()
-        if response == Gtk.RESPONSE_OK and deluge.common.is_infohash(infohash):
+        if response == Gtk.ResponseType.OK and deluge.common.is_infohash(infohash):
             # Create a list of trackers from the textview buffer
             tview_buf = textview.get_buffer()
             trackers_text = tview_buf.get_text(*tview_buf.get_bounds())
diff --git a/deluge/ui/gtk3/common.py b/deluge/ui/gtk3/common.py
index 84934de72..d05ad5d17 100644
--- a/deluge/ui/gtk3/common.py
+++ b/deluge/ui/gtk3/common.py
@@ -247,8 +247,11 @@ def associate_magnet_links(overwrite=False):
     elif not osx_check():
         # gconf method is only available in a GNOME environment
         try:
+            import gi
+
+            gi.require_version('GConf', '2.0')
             from gi.repository import GConf
-        except ImportError:
+        except ValueError:
             log.debug(
                 'gconf not available, so will not attempt to register magnet uri handler'
             )
diff --git a/deluge/ui/gtk3/connectionmanager.py b/deluge/ui/gtk3/connectionmanager.py
index 614758b09..6496a4f3d 100644
--- a/deluge/ui/gtk3/connectionmanager.py
+++ b/deluge/ui/gtk3/connectionmanager.py
@@ -322,7 +322,7 @@ class ConnectionManager(component.Component):
             dialog = AuthenticationDialog(reason.value.message, reason.value.username)
 
             def dialog_finished(response_id):
-                if response_id == Gtk.RESPONSE_OK:
+                if response_id == Gtk.ResponseType.OK:
                     self._connect(host_id, dialog.get_username(), dialog.get_password())
 
             return dialog.run().addCallback(dialog_finished)
diff --git a/deluge/ui/gtk3/edittrackersdialog.py b/deluge/ui/gtk3/edittrackersdialog.py
index 8ea2c726d..d958f6595 100644
--- a/deluge/ui/gtk3/edittrackersdialog.py
+++ b/deluge/ui/gtk3/edittrackersdialog.py
@@ -29,7 +29,7 @@ def last_tier_trackers_from_liststore(trackers_liststore):
     """Create a list of tracker from existing liststore and find last tier number.
 
     Args:
-        tracker_liststore (Gtk.ListStore): A gtk.ListStore with [tier (int), tracker (str)] rows.
+        tracker_liststore (Gtk.ListStore): A Gtk.ListStore with [tier (int), tracker (str)] rows.
 
     Returns:
         tuple(int, list): A tuple containing last tier number and list of trackers.
diff --git a/deluge/ui/gtk3/files_tab.py b/deluge/ui/gtk3/files_tab.py
index ec6b7c2b5..1716d6d80 100644
--- a/deluge/ui/gtk3/files_tab.py
+++ b/deluge/ui/gtk3/files_tab.py
@@ -821,9 +821,9 @@ class FilesTab(Tab):
         self, treeview, context, x, y, selection, info, etime
     ):
         try:
-            selected = pickle.loads(selection.data)
+            selected = pickle.loads(selection.get_data())
         except pickle.UnpicklingError:
-            log.debug('Invalid selection data: %s', selection.data)
+            log.debug('Invalid selection data: %s', selection.get_data())
             return
         log.debug('selection.data: %s', selected)
         drop_info = treeview.get_dest_row_at_pos(x, y)
diff --git a/deluge/ui/gtk3/gtkui.py b/deluge/ui/gtk3/gtkui.py
index f0e363bdc..8f872e94b 100644
--- a/deluge/ui/gtk3/gtkui.py
+++ b/deluge/ui/gtk3/gtkui.py
@@ -354,7 +354,7 @@ class GtkUI(object):
 
         def on_dialog_response(response):
             """User response to switching mode dialog."""
-            if response == ResponseType.Yes:
+            if response == ResponseType.YES:
                 # Turning off standalone
                 self.config['standalone'] = False
                 self._start_thinclient()
diff --git a/deluge/ui/gtk3/piecesbar.py b/deluge/ui/gtk3/piecesbar.py
index 427bd8f44..3b31eecdf 100644
--- a/deluge/ui/gtk3/piecesbar.py
+++ b/deluge/ui/gtk3/piecesbar.py
@@ -17,7 +17,7 @@ gi.require_version('PangoCairo', '1.0')  # NOQA: E402
 
 # isort:imports-thirdparty
 from gi.repository import PangoCairo, cairo
-from gi.repository.Gtk import DrawingArea, ProgressBar
+from gi.repository.Gtk import DrawingArea, ProgressBar, StateFlags
 from gi.repository.Pango import SCALE, Weight
 
 # isort:imports-firstparty
@@ -36,7 +36,7 @@ class PiecesBar(DrawingArea):
         # Get progress bar styles, in order to keep font consistency
         pb = ProgressBar()
         pb_style = pb.get_style_context()
-        self.text_font = pb_style.get_property('font', Gtk.StateFlags.NORMAL)
+        self.text_font = pb_style.get_property('font', StateFlags.NORMAL)
         self.text_font.set_weight(Weight.BOLD)
         # Done with the ProgressBar styles, don't keep refs of it
         del pb, pb_style