diff --git a/extension/prefs.js b/extension/prefs.js
index 93ab15e5..608034a7 100644
--- a/extension/prefs.js
+++ b/extension/prefs.js
@@ -31,13 +31,13 @@ const Lang = imports.lang;
 const ExtensionUtils = imports.misc.extensionUtils;
 const Me = ExtensionUtils.getCurrentExtension();
 
-const HamsterSettingsWidget = new GObject.Class({
-    Name: 'ProjectHamster.Prefs.HamsterSettingsWidget',
-    GTypeName: 'HamsterSettingsWidget',
-    Extends: Gtk.VBox,
+const HamsterSettingsWidget = GObject.registerClass(
+class HamsterSettingsWidget extends Gtk.VBox {
+    _init(params) {
+        super._init(params);
+
+        this.name = 'ProjectHamster.Prefs.HamsterSettingsWidget';
 
-    _init : function(params) {
-        this.parent(params);
         this.margin = 10;
 
         this._settings = ExtensionUtils.getSettings();
@@ -114,9 +114,9 @@ const HamsterSettingsWidget = new GObject.Class({
         let version_text = ExtensionUtils.getCurrentExtension().metadata.version;
         let version_label_text = "You are running hamster-shell-extension version " + version_text;
         vbox.add(new Gtk.Label({label: version_label_text, margin_top: 10}));
-    },
+    }
 
-    _onPlacementChange: function(widget) {
+    _onPlacementChange(widget) {
         let [success, iter] = widget.get_active_iter();
         if (!success)
             return;
@@ -127,9 +127,9 @@ const HamsterSettingsWidget = new GObject.Class({
             return;
 
         this._settings.set_int("panel-placement", newPlacement);
-    },
+    }
 
-    _onAppearanceChange: function(widget) {
+    _onAppearanceChange(widget) {
         let [success, iter] = widget.get_active_iter();
         if (!success)
             return;
@@ -140,9 +140,9 @@ const HamsterSettingsWidget = new GObject.Class({
             return;
 
         this._settings.set_int("panel-appearance", newAppearance);
-    },
+    }
 
-    _onHotkeyChange: function(widget, bananas) {
+    _onHotkeyChange(widget, bananas) {
         //global.log(widget, bananas);
         let hotkey = widget.get_text();
         let [key, mods] = Gtk.accelerator_parse(hotkey);
diff --git a/extension/widgets/categoryTotalsWidget.js b/extension/widgets/categoryTotalsWidget.js
index 683fe920..17af7473 100644
--- a/extension/widgets/categoryTotalsWidget.js
+++ b/extension/widgets/categoryTotalsWidget.js
@@ -25,6 +25,7 @@ const Lang = imports.lang;
 const St = imports.gi.St;
 const Clutter = imports.gi.Clutter;
 const GLib = imports.gi.GLib;
+const GObject = imports.gi.GObject;
 
 const Me = imports.misc.extensionUtils.getCurrentExtension();
 const Stuff = Me.imports.stuff;
@@ -33,19 +34,16 @@ const Stuff = Me.imports.stuff;
 /**
  * Custom Label widget that displays category totals.
  */
-var CategoryTotalsWidget = new Lang.Class({
-    Name: 'CategoryTotals',
-    Extends: St.Label,
-
-    _init: function() {
-        this.parent({style_class: 'summary-label'});
-
-    },
+var CategoryTotalsWidget = GObject.registerClass(
+class CategoryTotals extends St.Label {
+    _init() {
+        super._init({style_class: 'summary-label'});
+    }
 
     /**
      * Recompute values and replace old string with new one based on passed facts.
      */
-    refresh: function(facts) {
+    refresh(facts) {
         /**
          * Construct a string representing category totals.
          */
@@ -67,5 +65,5 @@ var CategoryTotalsWidget = new Lang.Class({
         }
 
         this.set_text(getString(facts));
-    },
+    }
 });
diff --git a/extension/widgets/factsBox.js b/extension/widgets/factsBox.js
index 42857f5a..aa5a3369 100644
--- a/extension/widgets/factsBox.js
+++ b/extension/widgets/factsBox.js
@@ -27,6 +27,7 @@ const PopupMenu = imports.ui.popupMenu;
 const Clutter = imports.gi.Clutter;
 const Mainloop = imports.mainloop;
 const GLib = imports.gi.GLib;
+const GObject = imports.gi.GObject;
 
 const Gettext = imports.gettext.domain('hamster-shell-extension');
 const _ = Gettext.gettext;
@@ -43,11 +44,10 @@ const TodaysFactsWidget = Me.imports.widgets.todaysFactsWidget.TodaysFactsWidget
  * well as todays facts.
  * @class
  */
-var FactsBox = new Lang.Class({
-    Name: 'FactsBox',
-    Extends: PopupMenu.PopupBaseMenuItem,
-    _init: function(controller, panelWidget) {
-        this.parent({reactive: false});
+var FactsBox =
+class FactsBox extends PopupMenu.PopupBaseMenuItem {
+    constructor(controller, panelWidget) {
+        super({reactive: false});
 
         this._controller = controller;
 
@@ -79,32 +79,32 @@ var FactsBox = new Lang.Class({
         // Setup category summery
         this.summaryLabel = new CategoryTotalsWidget();
         main_box.add(this.summaryLabel);
-    },
+    }
 
     // [FIXME]
     // The best solution would be to listen for a 'FactsChanged' Signal that carries the new
     // facts as payload and just refresh with this. But for now we stick with this
     // simpler version.
-    refresh: function(facts, ongoingFact) {
+    refresh(facts, ongoingFact) {
         this.todaysFactsWidget.refresh(facts, ongoingFact);
         this.summaryLabel.refresh(facts);
 
-    },
+    }
 
     /**
      * Focus the fact entry and make sure todaysFactsWidget are scrolled to the bottom.
      */
-    focus: function() {
+    focus() {
         Mainloop.timeout_add(20, Lang.bind(this, function() {
             this._scrollAdjustment.value = this._scrollAdjustment.upper;
             global.stage.set_key_focus(this.ongoingFactEntry);
         }));
-    },
+    }
 
     /**
      * Remove any existing focus.
      */
-    unfocus: function() {
+    unfocus() {
         global.stage.set_key_focus(null);
-    },
-});
+    }
+};
diff --git a/extension/widgets/ongoingFactEntry.js b/extension/widgets/ongoingFactEntry.js
index a46948d0..b90238e1 100644
--- a/extension/widgets/ongoingFactEntry.js
+++ b/extension/widgets/ongoingFactEntry.js
@@ -22,6 +22,7 @@ Copyright (c) 2016 - 2018 Eric Goller / projecthamster <elbenfreund@projecthamst
 
 
 const Lang = imports.lang;
+const GObject = imports.gi.GObject;
 const St = imports.gi.St;
 const Clutter = imports.gi.Clutter;
 
@@ -39,12 +40,10 @@ const Me = imports.misc.extensionUtils.getCurrentExtension();
  *
  *
  */
-var OngoingFactEntry = new Lang.Class({
-    Name: 'OngoingFactEntry',
-    Extends: St.Entry,
-
-    _init: function(controller) {
-        this.parent({
+var OngoingFactEntry = GObject.registerClass(
+class OngoingFactEntry extends St.Entry {
+    _init(controller) {
+        super._init({
             name: 'searchEntry',
             can_focus: true,
             track_hover: true,
@@ -59,7 +58,7 @@ var OngoingFactEntry = new Lang.Class({
         this._runningActivitiesQuery = null;
         this.clutter_text.connect('activate', Lang.bind(this, this._onEntryActivated));
         this.clutter_text.connect('key-release-event', Lang.bind(this, this._onKeyReleaseEvent));
-    },
+    }
 
     /**
      * Callback for when ``ongoingFactEntry`` gets activated.
@@ -70,13 +69,13 @@ var OngoingFactEntry = new Lang.Class({
      *
      * @callback FactsBox~_onEntryActivated
      */
-    _onEntryActivated: function() {
+    _onEntryActivated() {
         let text = this.get_text();
         this._controller.apiProxy.AddFactRemote(text, 0, 0, false, Lang.bind(this, function(response, error) {
             // not interested in the new id - this shuts up the warning
         }));
         this.set_text('');
-    },
+    }
 
     /**
      * Callback triggered after key release.
@@ -85,7 +84,7 @@ var OngoingFactEntry = new Lang.Class({
      *
      * @callback FactsBox~_onKeyReleaseEvent
      */
-    _onKeyReleaseEvent: function(textItem, evt) {
+    _onKeyReleaseEvent(textItem, evt) {
         /**
          * Check if the passed key is on our list of keys to be ignored.
          */
@@ -185,5 +184,5 @@ var OngoingFactEntry = new Lang.Class({
                 this._prevText = completion.toLowerCase();
             }
         }
-    },
+    }
 });
diff --git a/extension/widgets/panelWidget.js b/extension/widgets/panelWidget.js
index d43833d9..7328ba03 100644
--- a/extension/widgets/panelWidget.js
+++ b/extension/widgets/panelWidget.js
@@ -23,6 +23,7 @@ Copyright (c) 2016 - 2018 Eric Goller / projecthamster <elbenfreund@projecthamst
 
 const Lang = imports.lang;
 const Gio = imports.gi.Gio;
+const GObject = imports.gi.GObject;
 const Clutter = imports.gi.Clutter;
 const PanelMenu = imports.ui.panelMenu;
 const St = imports.gi.St;
@@ -55,14 +56,12 @@ const Stuff = Me.imports.stuff;
  *
  * @class
  */
-var PanelWidget = new Lang.Class({
-    Name: 'PanelWidget',
-    Extends: PanelMenu.Button,
-
-    _init: function(controller) {
+var PanelWidget = GObject.registerClass(
+class PanelWidget extends PanelMenu.Button {
+    _init(controller) {
         // [FIXME]
         // What is the parameter?
-        this.parent(0.0);
+        super._init(0.0);
 
         this._controller = controller;
         // [FIXME]
@@ -140,7 +139,7 @@ var PanelWidget = new Lang.Class({
         this.timeout = GLib.timeout_add_seconds(0, 60, Lang.bind(this, this.refresh));
         this.connect('destroy', Lang.bind(this, this._disableRefreshTimer));
         this.refresh();
-    },
+    }
 
     /**
      * This is our main 'update/refresh' method.
@@ -152,7 +151,7 @@ var PanelWidget = new Lang.Class({
      * required facts etc and pass them to the relevant sub-widget's
      * refresh methods.
      */
-    refresh: function() {
+    refresh() {
     /**
      * We need to wrap our actual refresh code in this callback for now as
      * I am having major difficulties using a syncronous dbus method call to
@@ -197,21 +196,21 @@ var PanelWidget = new Lang.Class({
     // here.
     this._controller.apiProxy.GetTodaysFactsRemote(Lang.bind(this, _refresh));
     return GLib.SOURCE_CONTINUE;
-    },
+    }
 
     /**
      * Open 'popup menu' containing the bulk of the extension widgets.
      */
-    show: function() {
+    show() {
         this.menu.open();
-    },
+    }
 
     /**
      * Close/Open the 'popup menu' depending on previous state.
      */
-    toggle: function() {
+    toggle() {
         this.menu.toggle();
-    },
+    }
 
 
     /**
@@ -220,7 +219,7 @@ var PanelWidget = new Lang.Class({
      * Depending on the 'display mode' set in the extensions settings this has
      * slightly different consequences.
      */
-    updatePanelDisplay: function(fact) {
+    updatePanelDisplay(fact) {
         /**
          * Return a text string representing the passed fact suitable for the panelLabel.
          *
@@ -262,7 +261,7 @@ var PanelWidget = new Lang.Class({
                 this.panelLabel.show();
                 break;
         }
-    },
+    }
 
     /**
      * Disable the refresh timer.
@@ -272,9 +271,9 @@ var PanelWidget = new Lang.Class({
      * This method is actually a callback triggered on the destroy
      * signal.
      */
-    _disableRefreshTimer: function() {
+    _disableRefreshTimer() {
         GLib.source_remove(this.timeout);
-    },
+    }
 
     /**
      * Callback to be triggered when an *ongoing fact* is stopped.
@@ -283,7 +282,7 @@ var PanelWidget = new Lang.Class({
      * This will get the current time and issue the ``StopTracking``
      * method call to the dbus interface.
      */
-    _onStopTracking: function() {
+    _onStopTracking() {
         let now = new Date();
         let epochSeconds = Date.UTC(now.getFullYear(),
                                     now.getMonth(),
@@ -293,25 +292,25 @@ var PanelWidget = new Lang.Class({
                                     now.getSeconds());
         epochSeconds = Math.floor(epochSeconds / 1000);
         this._controller.apiProxy.StopTrackingRemote(GLib.Variant.new('i', [epochSeconds]));
-    },
+    }
 
     /**
      * Callback that triggers opening of the *Overview*-Window.
      *
      * @callback panelWidget~_onOpenOverview
      */
-    _onOpenOverview: function() {
+    _onOpenOverview() {
         this._controller.windowsProxy.overviewSync();
-    },
+    }
 
     /**
      * Callback that triggers opening of the *Add Fact*-Window.
      *
      * @callback panelWidget~_onOpenAddFact
      */
-    _onOpenAddFact: function() {
+    _onOpenAddFact() {
         this._controller.windowsProxy.editSync(GLib.Variant.new('i', [0]));
-    },
+    }
 
     /**
      * Callback that triggers opening of the *Add Fact*-Window.
@@ -320,7 +319,7 @@ var PanelWidget = new Lang.Class({
      *
      * Note: This will open the GUI settings, not the extension settings!
      */
-    _onOpenSettings: function() {
+    _onOpenSettings() {
         this._controller.windowsProxy.preferencesSync();
-    },
+    }
 });
diff --git a/extension/widgets/todaysFactsWidget.js b/extension/widgets/todaysFactsWidget.js
index 1ec2de34..1b7f84a4 100644
--- a/extension/widgets/todaysFactsWidget.js
+++ b/extension/widgets/todaysFactsWidget.js
@@ -25,6 +25,7 @@ const Lang = imports.lang;
 const St = imports.gi.St;
 const Clutter = imports.gi.Clutter;
 const GLib = imports.gi.GLib;
+const GObject = imports.gi.GObject;
 
 const Me = imports.misc.extensionUtils.getCurrentExtension();
 const Stuff = Me.imports.stuff;
@@ -33,12 +34,10 @@ const Stuff = Me.imports.stuff;
 /**
  * A widget that lists all facts for *today*.
  */
-var TodaysFactsWidget = new Lang.Class({
-    Name: 'TodaysFactsWidget',
-    Extends: St.ScrollView,
-
-    _init: function(controller, panelWidget) {
-        this.parent({style_class: 'hamster-scrollbox'});
+var TodaysFactsWidget = GObject.registerClass(
+class TodaysFactsWidget extends St.ScrollView {
+    _init(controller, panelWidget) {
+        super._init({style_class: 'hamster-scrollbox'});
         this._controller = controller;
         this._panelWidget = panelWidget;
 
@@ -53,12 +52,12 @@ var TodaysFactsWidget = new Lang.Class({
         this.factsBox.add(this.facts_widget);
         this.add_actor(this.factsBox);
 
-    },
+    }
 
     /**
      * Populate the widget with rows representing the passed facts.
      */
-    populateFactsWidget: function(facts, ongoingFact) {
+    populateFactsWidget(facts, ongoingFact) {
 
         /**
          * Construct an individual row within the widget - representing a single fact.
@@ -181,13 +180,13 @@ var TodaysFactsWidget = new Lang.Class({
             }
             rowCount += 1;
         }
-    },
+    }
 
     /**
      * Clear the widget and populate it anew.
      */
-    refresh: function(facts, ongoingFact) {
+    refresh(facts, ongoingFact) {
         this.facts_widget.remove_all_children();
         this.populateFactsWidget(facts, ongoingFact);
-    },
+    }
 });