diff --git a/js/ui/barLevel.js b/js/ui/barLevel.js
index c4072e2cf..d2f961ce2 100644
--- a/js/ui/barLevel.js
+++ b/js/ui/barLevel.js
@@ -105,7 +105,7 @@ var BarLevel = class {
             overdriveSeparatorWidth = themeNode.get_length('-barlevel-overdrive-separator-width');
 
         /* background bar */
-        cr.arc(width - barLevelBorderRadius - barLevelBorderWidth, height / 2, barLevelBorderRadius, TAU * 3 / 4, TAU * 1 / 4);
+        cr.arc(width - barLevelBorderRadius - barLevelBorderWidth, height / 2, barLevelBorderRadius, TAU * (3 / 4), TAU * (1 / 4));
         cr.lineTo(endX, (height + barLevelHeight) / 2);
         cr.lineTo(endX, (height - barLevelHeight) / 2);
         cr.lineTo(width - barLevelBorderRadius - barLevelBorderWidth, (height - barLevelHeight) / 2);
@@ -117,7 +117,7 @@ var BarLevel = class {
 
         /* normal progress bar */
         let x = Math.min(endX, overdriveSeparatorX - overdriveSeparatorWidth / 2);
-        cr.arc(barLevelBorderRadius + barLevelBorderWidth, height / 2, barLevelBorderRadius, TAU * 1 / 4, TAU * 3 / 4);
+        cr.arc(barLevelBorderRadius + barLevelBorderWidth, height / 2, barLevelBorderRadius, TAU * (1 / 4), TAU * (3 / 4));
         cr.lineTo(x, (height - barLevelHeight) / 2);
         cr.lineTo(x, (height + barLevelHeight) / 2);
         cr.lineTo(barLevelBorderRadius + barLevelBorderWidth, (height + barLevelHeight) / 2);
@@ -149,7 +149,7 @@ var BarLevel = class {
               Clutter.cairo_set_source_color(cr, barLevelActiveColor);
           else
               Clutter.cairo_set_source_color(cr, barLevelOverdriveColor);
-          cr.arc(endX, height / 2, barLevelBorderRadius, TAU * 3 / 4, TAU * 1 / 4);
+          cr.arc(endX, height / 2, barLevelBorderRadius, TAU * (3 / 4), TAU * (1 / 4));
           cr.lineTo(Math.floor(endX), (height + barLevelHeight) / 2);
           cr.lineTo(Math.floor(endX), (height - barLevelHeight) / 2);
           cr.lineTo(endX, (height - barLevelHeight) / 2);
diff --git a/js/ui/extensionSystem.js b/js/ui/extensionSystem.js
index 744f5e7ac..a53838d58 100644
--- a/js/ui/extensionSystem.js
+++ b/js/ui/extensionSystem.js
@@ -147,7 +147,7 @@ function logExtensionError(uuid, error) {
     if (!extension)
         return;
 
-    let message = '' + error;
+    let message = `${error}`;
 
     extension.state = ExtensionState.ERROR;
     if (!extension.errors)
diff --git a/js/ui/lookingGlass.js b/js/ui/lookingGlass.js
index 3149cf421..edcfdecc8 100644
--- a/js/ui/lookingGlass.js
+++ b/js/ui/lookingGlass.js
@@ -242,7 +242,7 @@ function objectToString(o) {
         // special case this since the default is way, way too verbose
         return '<js function>';
     } else {
-        return '' + o;
+        return `${o}`;
     }
 }
 
diff --git a/js/ui/main.js b/js/ui/main.js
index abd83721c..ea0a93984 100644
--- a/js/ui/main.js
+++ b/js/ui/main.js
@@ -658,7 +658,7 @@ function _queueBeforeRedraw(workId) {
  */
 function initializeDeferredWork(actor, callback, props) {
     // Turn into a string so we can use as an object property
-    let workId = '' + (++_deferredWorkSequence);
+    let workId = `${(++_deferredWorkSequence)}`;
     _deferredWorkData[workId] = { 'actor': actor,
                                   'callback': callback };
     actor.connect('notify::mapped', () => {
diff --git a/js/ui/shellDBus.js b/js/ui/shellDBus.js
index 19d07acce..a9224f841 100644
--- a/js/ui/shellDBus.js
+++ b/js/ui/shellDBus.js
@@ -65,7 +65,7 @@ var GnomeShell = class {
                 returnValue = '';
             success = true;
         } catch (e) {
-            returnValue = '' + e;
+            returnValue = `${e}`;
             success = false;
         }
         return [success, returnValue];
diff --git a/js/ui/slider.js b/js/ui/slider.js
index 3c1b35e05..4025a11fd 100644
--- a/js/ui/slider.js
+++ b/js/ui/slider.js
@@ -142,7 +142,7 @@ var Slider = class extends BarLevel.BarLevel {
         if (direction == Clutter.ScrollDirection.DOWN) {
             delta = -SLIDER_SCROLL_STEP;
         } else if (direction == Clutter.ScrollDirection.UP) {
-            delta = +SLIDER_SCROLL_STEP;
+            delta = SLIDER_SCROLL_STEP;
         } else if (direction == Clutter.ScrollDirection.SMOOTH) {
             let [dx, dy] = event.get_scroll_delta();
             // Even though the slider is horizontal, use dy to match