diff --git a/src/vs/workbench/browser/viewlet.ts b/src/vs/workbench/browser/viewlet.ts
index 8ac7d316645a02bf6f4387553179c7dad6b2f35a..5cf9a18e830cdf97a51e3aa69521dd6448a1c539 100644
--- a/src/vs/workbench/browser/viewlet.ts
+++ b/src/vs/workbench/browser/viewlet.ts
@@ -540,7 +540,6 @@ export class CollapsibleViewletView extends CollapsibleView implements IViewletV
 
 function renderViewTree(container: HTMLElement): HTMLElement {
 	let treeContainer = document.createElement('div');
-	DOM.addClass(treeContainer, 'explorer-view-content');
 	container.appendChild(treeContainer);
 
 	return treeContainer;
diff --git a/src/vs/workbench/parts/debug/browser/debugViewlet.ts b/src/vs/workbench/parts/debug/browser/debugViewlet.ts
index a05256a51b1b6028a362e94f2ffd3dba87fbaaa0..9c9673d5058c33589a8447315086260bdcc96659 100644
--- a/src/vs/workbench/parts/debug/browser/debugViewlet.ts
+++ b/src/vs/workbench/parts/debug/browser/debugViewlet.ts
@@ -469,6 +469,12 @@ export class DebugViewlet extends viewlet.Viewlet {
 		return Promise.as(null);
 	}
 
+	public setVisible(visible: boolean): TPromise<void> {
+		return super.setVisible(visible).then(() => {
+			return Promise.join(this.views.map((view) => view.setVisible(visible)));
+		});
+	}
+
 	public layout(dimension: builder.Dimension): void {
 		if (this.splitView) {
 			this.splitView.layout(dimension.height);