diff --git a/extension.js b/extension.js
index 0de8d85..ffd1e2f 100644
--- a/extension.js
+++ b/extension.js
@@ -13,6 +13,9 @@ const PopupMenu = imports.ui.popupMenu;
 const St = imports.gi.St;
 const Tweener = imports.tweener && imports.tweener.tweener || imports.ui.tweener;
 
+const Config = imports.misc.config;
+const SHELL_VERSION_MAJOR = parseInt(Config.PACKAGE_VERSION.split('.')[0]);
+
 let onWindowGrabBegin, onWindowGrabEnd;
 let windowMoving = false;
 
@@ -65,7 +68,6 @@ updateSettings();
 // Watch the settings for changes
 let settingsChangedId = settings.connect('changed', updateSettings.bind());
 
-const Config = imports.misc.config;
 window.wintile = {
 	extdatadir: imports.misc.extensionUtils.getCurrentExtension().path,
 	shell_version: parseInt(Config.PACKAGE_VERSION.split('.')[1], 10)
@@ -647,7 +649,7 @@ function checkForMove(x, y, app) {
 	}
 }
 
-function windowGrabBegin(meta_display, meta_screen, meta_window, meta_grab_op, gpointer) {
+function windowGrabBegin(meta_window, meta_grab_op) {
 	_log('windowGrabBegin')
 	if (meta_window) {
 		windowMoving = true;
@@ -665,7 +667,7 @@ function windowGrabBegin(meta_display, meta_screen, meta_window, meta_grab_op, g
 	}
 }
 
-function windowGrabEnd(meta_display, meta_screen, meta_window, meta_grab_op, gpointer) {
+function windowGrabEnd(meta_window, meta_grab_op) {
 	_log('windowGrabEnd')
 	if (meta_window) {
 		windowMoving = false;
@@ -879,8 +881,23 @@ var enable = function() {
 			keyManager.add("<Super>up", function() { requestMove("up") })
 			keyManager.add("<Super>down", function() { requestMove("down") })
 		});
-		onWindowGrabBegin = global.display.connect('grab-op-begin', windowGrabBegin);
-		onWindowGrabEnd = global.display.connect('grab-op-end', windowGrabEnd);
+
+		// Since GNOME 40 the meta_display argument isn't passed anymore to these callbacks.
+		// We "translate" the parameters here so that things work on both GNOME 3 and 40.
+		onWindowGrabBegin = global.display.connect('grab-op-begin', (meta_display, meta_screen, meta_window, meta_grab_op, gpointer) => {
+			if (SHELL_VERSION_MAJOR >= 40) { 
+				windowGrabBegin(meta_screen, meta_window);
+			} else {
+				windowGrabBegin(meta_window, meta_grab_op);
+			}
+		});
+		onWindowGrabEnd = global.display.connect('grab-op-end', (meta_display, meta_screen, meta_window, meta_grab_op, gpointer) => {
+			if (SHELL_VERSION_MAJOR >= 40) { 
+				windowGrabEnd(meta_screen, meta_window);
+			} else {
+				windowGrabEnd(meta_window, meta_grab_op);
+			}
+		});
 	}
 }
 
diff --git a/keybindings.js b/keybindings.js
index 72c8532..ade63cf 100644
--- a/keybindings.js
+++ b/keybindings.js
@@ -5,6 +5,7 @@ const Main = imports.ui.main;
 const Meta = imports.gi.Meta;
 const Shell = imports.gi.Shell;
 
+const SHELL_VERSION_MAJOR = parseInt(Config.PACKAGE_VERSION.split('.')[0]);
 const SHELL_VERSION_MINOR = parseInt(Config.PACKAGE_VERSION.split('.')[1]);
 
 
@@ -57,10 +58,10 @@ var Manager = class Manager {
         let action = Meta.KeyBindingAction.NONE;
 
         // A flags argument was added somewhere between 3.30-3.32
-        if (SHELL_VERSION_MINOR > 30) {
-            action = global.display.grab_accelerator(accelerator, 0);
-        } else {
+        if (SHELL_VERSION_MAJOR == 3 && SHELL_VERSION_MINOR < 30) {
             action = global.display.grab_accelerator(accelerator);
+        } else {
+            action = global.display.grab_accelerator(accelerator, 0);
         }
 
         if (action !== Meta.KeyBindingAction.NONE) {
diff --git a/metadata.json b/metadata.json
index bdf7638..c5d4863 100644
--- a/metadata.json
+++ b/metadata.json
@@ -9,7 +9,8 @@
 		"3.32",
 		"3.34",
 		"3.36",
-		"3.38"
+		"3.38",
+		"40.0"
 	],
 	"version": 6
 }
diff --git a/prefs.js b/prefs.js
index 1769c6a..7359861 100644
--- a/prefs.js
+++ b/prefs.js
@@ -10,6 +10,9 @@ const Me = ExtensionUtils.getCurrentExtension();
 const Gettext = imports.gettext;
 const _ = Gettext.domain('wintile').gettext;
 
+const Config = imports.misc.config;
+const SHELL_VERSION_MAJOR = parseInt(Config.PACKAGE_VERSION.split('.')[0]);
+
 let gschema = Gio.SettingsSchemaSource.new_from_directory(
     Me.dir.get_child('schemas').get_path(),
     Gio.SettingsSchemaSource.get_default(),
@@ -45,7 +48,10 @@ function buildPrefsWidget() {
 
     // Create a parent widget that we'll return from this function
     let layout = new Gtk.Grid({
-        margin: 18,
+        margin_bottom: 18,
+        margin_end: 18,
+        margin_start: 18,
+        margin_top: 18,
         column_spacing: 12,
         row_spacing: 12,
         visible: true
@@ -161,7 +167,11 @@ function buildPrefsWidget() {
         visible: true
     });    
     previewDistanceSettingInt.set_value(gsettings.get_int('distance'));
-    previewDistanceInput.add(previewDistanceSettingInt);
+    if (SHELL_VERSION_MAJOR >= 40) {
+        previewDistanceInput.append(previewDistanceSettingInt);
+    } else {
+        previewDistanceInput.add(previewDistanceSettingInt);
+    }
     layout.attach(previewDistanceLabel, 0, row, 1, 1);
     layout.attach(previewDistanceInput, 1, row++, 1, 1);
 
@@ -187,7 +197,11 @@ function buildPrefsWidget() {
         visible: true
     });    
     previewDelaySettingInt.set_value(gsettings.get_int('delay'));
-    previewDelayInput.add(previewDelaySettingInt);
+    if (SHELL_VERSION_MAJOR >= 40) {
+        previewDelayInput.append(previewDelaySettingInt);
+    } else {
+        previewDelayInput.add(previewDelaySettingInt);
+    }
     layout.attach(previewDelayLabel, 0, row, 1, 1);
     layout.attach(previewDelayInput, 1, row++, 1, 1);