diff --git a/src/vs/workbench/api/browser/viewsExtensionPoint.ts b/src/vs/workbench/api/browser/viewsExtensionPoint.ts
index 8bace468433..7a2b3b679e5 100644
--- a/src/vs/workbench/api/browser/viewsExtensionPoint.ts
+++ b/src/vs/workbench/api/browser/viewsExtensionPoint.ts
@@ -327,7 +327,7 @@ class ViewsExtensionHandler implements IWorkbenchContribution {
 
 			// Generate CSS to show the icon in the activity bar
 			const iconClass = `.monaco-workbench .activitybar .monaco-action-bar .action-label.${cssClass}`;
-			createCSSRule(iconClass, `-webkit-mask: url('${icon}') no-repeat 50% 50%`);
+			createCSSRule(iconClass, `-webkit-mask: url('${icon}') no-repeat 50% 50%; -webkit-mask-size: 24px;`);
 		}
 
 		return viewContainer;
diff --git a/src/vs/workbench/browser/legacyLayout.ts b/src/vs/workbench/browser/legacyLayout.ts
index 202d19fa434..a1d936c0f1e 100644
--- a/src/vs/workbench/browser/legacyLayout.ts
+++ b/src/vs/workbench/browser/legacyLayout.ts
@@ -19,7 +19,7 @@ import { Part } from 'vs/workbench/browser/part';
 
 const TITLE_BAR_HEIGHT = isMacintosh && !isWeb ? 22 : 30;
 const STATUS_BAR_HEIGHT = 22;
-const ACTIVITY_BAR_WIDTH = 50;
+const ACTIVITY_BAR_WIDTH = 48;
 
 const MIN_SIDEBAR_PART_WIDTH = 170;
 const DEFAULT_SIDEBAR_PART_WIDTH = 300;
diff --git a/src/vs/workbench/browser/parts/activitybar/activitybarActions.ts b/src/vs/workbench/browser/parts/activitybar/activitybarActions.ts
index 24d8fe70c7f..1138e9db748 100644
--- a/src/vs/workbench/browser/parts/activitybar/activitybarActions.ts
+++ b/src/vs/workbench/browser/parts/activitybar/activitybarActions.ts
@@ -173,7 +173,7 @@ export class PlaceHolderViewletActivityAction extends ViewletActivityAction {
 		super({ id, name: id, cssClass: `extensionViewlet-placeholder-${id.replace(/\./g, '-')}` }, viewletService, layoutService, telemetryService);
 
 		const iconClass = `.monaco-workbench .activitybar .monaco-action-bar .action-label.${this.class}`; // Generate Placeholder CSS to show the icon in the activity bar
-		DOM.createCSSRule(iconClass, `-webkit-mask: url('${iconUrl || ''}') no-repeat 50% 50%`);
+		DOM.createCSSRule(iconClass, `-webkit-mask: url('${iconUrl || ''}') no-repeat 50% 50%; -webkit-mask-size: 24px;`);
 	}
 
 	setActivity(activity: IActivity): void {
diff --git a/src/vs/workbench/browser/parts/activitybar/activitybarPart.ts b/src/vs/workbench/browser/parts/activitybar/activitybarPart.ts
index d602a8ed768..430a560f520 100644
--- a/src/vs/workbench/browser/parts/activitybar/activitybarPart.ts
+++ b/src/vs/workbench/browser/parts/activitybar/activitybarPart.ts
@@ -48,13 +48,13 @@ export class ActivitybarPart extends Part implements IActivityBarService {
 
 	_serviceBrand: ServiceIdentifier<any>;
 
-	private static readonly ACTION_HEIGHT = 50;
+	private static readonly ACTION_HEIGHT = 48;
 	private static readonly PINNED_VIEWLETS = 'workbench.activity.pinnedViewlets';
 
 	//#region IView
 
-	readonly minimumWidth: number = 50;
-	readonly maximumWidth: number = 50;
+	readonly minimumWidth: number = 48;
+	readonly maximumWidth: number = 48;
 	readonly minimumHeight: number = 0;
 	readonly maximumHeight: number = Number.POSITIVE_INFINITY;
 
diff --git a/src/vs/workbench/browser/parts/activitybar/media/activityaction.css b/src/vs/workbench/browser/parts/activitybar/media/activityaction.css
index 362ea4a70c8..b7f64c06a08 100644
--- a/src/vs/workbench/browser/parts/activitybar/media/activityaction.css
+++ b/src/vs/workbench/browser/parts/activitybar/media/activityaction.css
@@ -15,7 +15,7 @@
 	height: 40px;
 	line-height: 40px;
 	margin-right: 0;
-	padding: 0 0 0 50px;
+	padding: 0 0 0 48px;
 	box-sizing: border-box;
 	font-size: 15px;
 }
diff --git a/src/vs/workbench/browser/parts/activitybar/media/activitybarpart.css b/src/vs/workbench/browser/parts/activitybar/media/activitybarpart.css
index 87fb7f94a58..ec58e4ab04f 100644
--- a/src/vs/workbench/browser/parts/activitybar/media/activitybarpart.css
+++ b/src/vs/workbench/browser/parts/activitybar/media/activitybarpart.css
@@ -4,7 +4,7 @@
  *--------------------------------------------------------------------------------------------*/
 
 .monaco-workbench .part.activitybar {
-	width: 50px;
+	width: 48px;
 }
 
 .monaco-workbench .activitybar > .content {