diff --git a/extensions/apps-menu/extension.js b/extensions/apps-menu/extension.js
index e2c9a9c3..d7e108d2 100644
--- a/extensions/apps-menu/extension.js
+++ b/extensions/apps-menu/extension.js
@@ -77,8 +77,8 @@ class ApplicationMenuItem extends PopupMenu.PopupBaseMenuItem {
         super.setActive(active, params);
     }
 
-    setDragEnabled(enable) {
-        this._dragEnabled = enable;
+    setDragEnabled(enabled) {
+        this._dragEnabled = enabled;
     }
 
     getDragActor() {
@@ -630,7 +630,7 @@ class ApplicationsButton extends PanelMenu.Button {
             this.applicationsByCategory[categoryId] = [];
             this._loadCategory(categoryId, dir);
             if (this.applicationsByCategory[categoryId].length > 0) {
-                let categoryMenuItem = new CategoryMenuItem(this, dir);
+                categoryMenuItem = new CategoryMenuItem(this, dir);
                 this.categoriesBox.add_actor(categoryMenuItem);
             }
         }
diff --git a/extensions/auto-move-windows/prefs.js b/extensions/auto-move-windows/prefs.js
index bd20aabe..f89a6692 100644
--- a/extensions/auto-move-windows/prefs.js
+++ b/extensions/auto-move-windows/prefs.js
@@ -147,13 +147,13 @@ const Widget = GObject.registerClass({
         grid.attach(dialog._spin, 1, 1, 1, 1);
         dialog.get_content_area().add(grid);
 
-        dialog.connect('response', (dialog, id) => {
+        dialog.connect('response', (dlg, id) => {
             if (id != Gtk.ResponseType.OK) {
                 dialog.destroy();
                 return;
             }
 
-            let appInfo = dialog._appChooser.get_app_info();
+            appInfo = dialog._appChooser.get_app_info();
             if (!appInfo)
                 return;
             let index = Math.floor(dialog._spin.value);
diff --git a/extensions/native-window-placement/extension.js b/extensions/native-window-placement/extension.js
index 8d39d0f9..383322f1 100644
--- a/extensions/native-window-placement/extension.js
+++ b/extensions/native-window-placement/extension.js
@@ -157,7 +157,7 @@ class NaturalLayoutStrategy extends Workspace.LayoutStrategy {
                             let xSection = Math.round((rects[i].x - bounds.x) / (bounds.width / 3));
                             let ySection = Math.round((rects[i].y - bounds.y) / (bounds.height / 3));
 
-                            let iCenter = rects[i].center();
+                            iCenter = rects[i].center();
                             diff[0] = 0;
                             diff[1] = 0;
                             if (xSection != 1 || ySection != 1) { // Remove this if you want the center to pull as well
@@ -183,7 +183,7 @@ class NaturalLayoutStrategy extends Workspace.LayoutStrategy {
                                 diff[1] = bounds.y + bounds.height - iCenter[1];
                             }
                             if (diff[0] != 0 || diff[1] != 0) {
-                                let length = Math.sqrt(diff[0] * diff[0] + diff[1] * diff[1]);
+                                length = Math.sqrt(diff[0] * diff[0] + diff[1] * diff[1]);
                                 diff[0] *= WINDOW_PLACEMENT_NATURAL_ACCURACY / length / 2;   // /2 to make it less influencing than the normal center-move above
                                 diff[1] *= WINDOW_PLACEMENT_NATURAL_ACCURACY / length / 2;
                                 rects[i].translate(diff[0], diff[1]);
diff --git a/extensions/places-menu/placeDisplay.js b/extensions/places-menu/placeDisplay.js
index add57bec..03189b93 100644
--- a/extensions/places-menu/placeDisplay.js
+++ b/extensions/places-menu/placeDisplay.js
@@ -41,9 +41,9 @@ class PlaceInfo {
     async _ensureMountAndLaunch(context, tryMount) {
         try {
             await this._launchDefaultForUri(this.file.get_uri(), context, null);
-        } catch (e) {
-            if (!e.matches(Gio.IOErrorEnum, Gio.IOErrorEnum.NOT_MOUNTED)) {
-                Main.notifyError(_('Failed to launch “%s”').format(this.name), e.message);
+        } catch (err) {
+            if (!err.matches(Gio.IOErrorEnum, Gio.IOErrorEnum.NOT_MOUNTED)) {
+                Main.notifyError(_('Failed to launch “%s”').format(this.name), err.message);
                 return;
             }
 
@@ -505,16 +505,16 @@ var PlacesManager = class {
                 continue;
 
             let duplicate = false;
-            for (let i = 0; i < this._places.special.length; i++) {
-                if (file.equal(this._places.special[i].file)) {
+            for (let j = 0; i < this._places.special.length; j++) {
+                if (file.equal(this._places.special[j].file)) {
                     duplicate = true;
                     break;
                 }
             }
             if (duplicate)
                 continue;
-            for (let i = 0; i < bookmarks.length; i++) {
-                if (file.equal(bookmarks[i].file)) {
+            for (let j = 0; j < bookmarks.length; j++) {
+                if (file.equal(bookmarks[j].file)) {
                     duplicate = true;
                     break;
                 }
diff --git a/extensions/window-list/workspaceIndicator.js b/extensions/window-list/workspaceIndicator.js
index 84dccacc..33b2e498 100644
--- a/extensions/window-list/workspaceIndicator.js
+++ b/extensions/window-list/workspaceIndicator.js
@@ -344,7 +344,7 @@ var WorkspaceIndicator = GObject.registerClass({
             let item = new PopupMenu.PopupMenuItem(name);
             item.workspaceId = i;
 
-            item.connect('activate', (item, _event) => {
+            item.connect('activate', () => {
                 this._activate(item.workspaceId);
             });