diff --git a/src/vs/workbench/browser/parts/activitybar/activitybarPart.ts b/src/vs/workbench/browser/parts/activitybar/activitybarPart.ts
index 845cbe3135da15bc44577965e1f8ca69f61b633c..25b87fbb851d1c3391bf5a4b0d4205fadfabb62d 100644
--- a/src/vs/workbench/browser/parts/activitybar/activitybarPart.ts
+++ b/src/vs/workbench/browser/parts/activitybar/activitybarPart.ts
@@ -48,6 +48,7 @@ export class ActivitybarPart extends Part {
 	private globalActivityIdToActions: { [globalActivityId: string]: GlobalActivityAction; };
 
 	private compositeBar: CompositeBar;
+	private compositeActions: { [compositeId: string]: { activityAction: ViewletActivityAction, pinnedAction: ToggleCompositePinnedAction } };
 
 	constructor(
 		id: string,
@@ -60,14 +61,15 @@ export class ActivitybarPart extends Part {
 
 		this.globalActivityIdToActions = Object.create(null);
 
+		this.compositeActions = Object.create(null);
 		this.compositeBar = this.instantiationService.createInstance(CompositeBar, {
 			icon: true,
 			storageId: ActivitybarPart.PINNED_VIEWLETS,
 			orientation: ActionsOrientation.VERTICAL,
 			composites: this.viewletService.getViewlets().filter(v => this.canShow(v)),
 			openComposite: (compositeId: string) => this.viewletService.openViewlet(compositeId, true),
-			getActivityAction: (compositeId: string) => this.instantiationService.createInstance(ViewletActivityAction, this.viewletService.getViewlet(compositeId)),
-			getCompositePinnedAction: (compositeId: string) => new ToggleCompositePinnedAction(this.viewletService.getViewlet(compositeId), this.compositeBar),
+			getActivityAction: (compositeId: string) => this.getCompositeActions(compositeId).activityAction,
+			getCompositePinnedAction: (compositeId: string) => this.getCompositeActions(compositeId).pinnedAction,
 			getOnCompositeClickAction: (compositeId: string) => this.instantiationService.createInstance(ToggleViewletAction, this.viewletService.getViewlet(compositeId)),
 			getContextMenuActions: () => [this.instantiationService.createInstance(ToggleActivityBarVisibilityAction, ToggleActivityBarVisibilityAction.ID, nls.localize('hideActivitBar', "Hide Activity Bar"))],
 			getDefaultCompositeId: () => this.viewletService.getDefaultViewletId(),
@@ -96,7 +98,7 @@ export class ActivitybarPart extends Part {
 			if (enabled) {
 				this.compositeBar.addComposite(this.viewletService.getViewlet(id), true);
 			} else {
-				this.compositeBar.removeComposite(id);
+				this.removeComposite(id);
 			}
 		}));
 	}
@@ -177,6 +179,18 @@ export class ActivitybarPart extends Part {
 		});
 	}
 
+	private getCompositeActions(compositeId: string): { activityAction: ViewletActivityAction, pinnedAction: ToggleCompositePinnedAction } {
+		let compositeActions = this.compositeActions[compositeId];
+		if (!compositeActions) {
+			compositeActions = {
+				activityAction: this.instantiationService.createInstance(ViewletActivityAction, this.viewletService.getViewlet(compositeId)),
+				pinnedAction: new ToggleCompositePinnedAction(this.viewletService.getViewlet(compositeId), this.compositeBar)
+			};
+			this.compositeActions[compositeId] = compositeActions;
+		}
+		return compositeActions;
+	}
+
 	private updateCompositebar(): void {
 		const viewlets = this.viewletService.getViewlets();
 		for (const viewlet of viewlets) {
@@ -189,11 +203,21 @@ export class ActivitybarPart extends Part {
 					this.compositeBar.activateComposite(viewlet.id);
 				}
 			} else {
-				this.compositeBar.removeComposite(viewlet.id);
+				this.removeComposite(viewlet.id);
 			}
 		}
 	}
 
+	private removeComposite(compositeId: string): void {
+		this.compositeBar.removeComposite(compositeId);
+		const compositeActions = this.compositeActions[compositeId];
+		if (compositeActions) {
+			compositeActions.activityAction.dispose();
+			compositeActions.pinnedAction.dispose();
+			delete this.compositeActions[compositeId];
+		}
+	}
+
 	private canShow(viewlet: ViewletDescriptor): boolean {
 		const viewLocation = ViewLocation.get(viewlet.id);
 		if (viewLocation) {
diff --git a/src/vs/workbench/browser/parts/compositebar/compositeBar.ts b/src/vs/workbench/browser/parts/compositebar/compositeBar.ts
index 20bd3c4a8581ecc5c58c6fbff12e28117b5bf099..0a542c0d61b2392c3b8bac18a64e8f6a9e887a28 100644
--- a/src/vs/workbench/browser/parts/compositebar/compositeBar.ts
+++ b/src/vs/workbench/browser/parts/compositebar/compositeBar.ts
@@ -478,7 +478,7 @@ interface ISerializedCompositeBarItem {
 	order: number;
 }
 
-interface ICompositeBarItem extends ISerializedCompositeBarItem, IDisposable {
+interface ICompositeBarItem extends ISerializedCompositeBarItem {
 	name: string;
 	activityAction: ActivityAction;
 	pinnedAction: Action;
@@ -494,28 +494,13 @@ class CompositeBarModel {
 
 	private createCompositeBarItem(id: string, name: string, order: number, pinned: boolean): ICompositeBarItem {
 		const options = this.options;
-		let activityAction, pinnedAction;
 		return {
 			id, name, pinned, order, activity: [],
 			get activityAction() {
-				if (!activityAction) {
-					activityAction = options.getActivityAction(id);
-				}
-				return activityAction;
+				return options.getActivityAction(id);
 			},
 			get pinnedAction() {
-				if (!pinnedAction) {
-					pinnedAction = options.getCompositePinnedAction(id);
-				}
-				return pinnedAction;
-			},
-			dispose: () => {
-				if (activityAction) {
-					activityAction.dispose();
-				}
-				if (pinnedAction) {
-					pinnedAction.dispose();
-				}
+				return options.getCompositePinnedAction(id);
 			}
 		};
 	}
@@ -541,8 +526,7 @@ class CompositeBarModel {
 	remove(id: string): boolean {
 		for (let index = 0; index < this.items.length; index++) {
 			if (this.items[index].id === id) {
-				const item = this.items.splice(index, 1)[0];
-				item.dispose();
+				this.items.splice(index, 1);
 				return true;
 			}
 		}
diff --git a/src/vs/workbench/browser/parts/panel/panelPart.ts b/src/vs/workbench/browser/parts/panel/panelPart.ts
index aaca0778ba72b63c11117c2debafeecaf0edc387..ff4240cb97ad966e371fbb7dd504d02fd054a5ae 100644
--- a/src/vs/workbench/browser/parts/panel/panelPart.ts
+++ b/src/vs/workbench/browser/parts/panel/panelPart.ts
@@ -42,6 +42,7 @@ export class PanelPart extends CompositePart<Panel> implements IPanelService {
 
 	private blockOpeningPanel: boolean;
 	private compositeBar: CompositeBar;
+	private compositeActions: { [compositeId: string]: { activityAction: PanelActivityAction, pinnedAction: ToggleCompositePinnedAction } };
 	private dimension: Dimension;
 
 	constructor(
@@ -74,14 +75,15 @@ export class PanelPart extends CompositePart<Panel> implements IPanelService {
 			{ hasTitle: true }
 		);
 
+		this.compositeActions = Object.create(null);
 		this.compositeBar = this.instantiationService.createInstance(CompositeBar, {
 			icon: false,
 			storageId: PanelPart.PINNED_PANELS,
 			orientation: ActionsOrientation.HORIZONTAL,
 			composites: this.getPanels(),
 			openComposite: (compositeId: string) => this.openPanel(compositeId, true),
-			getActivityAction: (compositeId: string) => this.instantiationService.createInstance(PanelActivityAction, this.getPanel(compositeId)),
-			getCompositePinnedAction: (compositeId: string) => new ToggleCompositePinnedAction(this.getPanel(compositeId), this.compositeBar),
+			getActivityAction: (compositeId: string) => this.getCompositeActions(compositeId).activityAction,
+			getCompositePinnedAction: (compositeId: string) => this.getCompositeActions(compositeId).pinnedAction,
 			getOnCompositeClickAction: (compositeId: string) => this.instantiationService.createInstance(PanelActivityAction, this.getPanel(compositeId)),
 			getContextMenuActions: () => [this.instantiationService.createInstance(TogglePanelAction, TogglePanelAction.ID, localize('hidePanel', "Hide Panel"))],
 			getDefaultCompositeId: () => Registry.as<PanelRegistry>(PanelExtensions.Panels).getDefaultPanelId(),
@@ -178,7 +180,7 @@ export class PanelPart extends CompositePart<Panel> implements IPanelService {
 					this.compositeBar.activateComposite(descriptor.id);
 				});
 			} else {
-				this.compositeBar.removeComposite(id);
+				this.removeComposite(id);
 			}
 		}
 	}
@@ -253,6 +255,28 @@ export class PanelPart extends CompositePart<Panel> implements IPanelService {
 		}
 	}
 
+	private getCompositeActions(compositeId: string): { activityAction: PanelActivityAction, pinnedAction: ToggleCompositePinnedAction } {
+		let compositeActions = this.compositeActions[compositeId];
+		if (!compositeActions) {
+			compositeActions = {
+				activityAction: this.instantiationService.createInstance(PanelActivityAction, this.getPanel(compositeId)),
+				pinnedAction: new ToggleCompositePinnedAction(this.getPanel(compositeId), this.compositeBar)
+			};
+			this.compositeActions[compositeId] = compositeActions;
+		}
+		return compositeActions;
+	}
+
+	private removeComposite(compositeId: string): void {
+		this.compositeBar.removeComposite(compositeId);
+		const compositeActions = this.compositeActions[compositeId];
+		if (compositeActions) {
+			compositeActions.activityAction.dispose();
+			compositeActions.pinnedAction.dispose();
+			delete this.compositeActions[compositeId];
+		}
+	}
+
 	private getToolbarWidth(): number {
 		const activePanel = this.getActivePanel();
 		if (!activePanel) {