diff --git a/src/vs/base/browser/ui/list/listWidget.ts b/src/vs/base/browser/ui/list/listWidget.ts
index f82c5788fe9b8be04e236e18f7c4b3d865c9bdc5..8026e676bdde8b25ac6d52b6dfadaae51081e345 100644
--- a/src/vs/base/browser/ui/list/listWidget.ts
+++ b/src/vs/base/browser/ui/list/listWidget.ts
@@ -388,7 +388,7 @@ const DefaultMultipleSelectionContoller = {
 	isSelectionRangeChangeEvent
 };
 
-const DefaultOpenController = {
+const DefaultOpenController: IOpenController = {
 	shouldOpen: (event: UIEvent) => {
 		if (event instanceof MouseEvent) {
 			return !isMouseRightClick(event);
@@ -396,7 +396,7 @@ const DefaultOpenController = {
 
 		return true;
 	}
-} as IOpenController;
+};
 
 class MouseController<T> implements IDisposable {
 
diff --git a/src/vs/editor/contrib/suggest/suggestWidget.ts b/src/vs/editor/contrib/suggest/suggestWidget.ts
index 4b904459a4886c456cd571b302dc2c80ad5b80f3..cf433d3dc8a0661f3a771e7f7206cc9f226a5d40 100644
--- a/src/vs/editor/contrib/suggest/suggestWidget.ts
+++ b/src/vs/editor/contrib/suggest/suggestWidget.ts
@@ -439,7 +439,8 @@ export class SuggestWidget implements IContentWidget, IDelegate<ICompletionItem>
 		this.list = new List(this.listElement, this, [renderer], {
 			useShadows: false,
 			selectOnMouseDown: true,
-			focusOnMouseDown: false
+			focusOnMouseDown: false,
+			openController: { shouldOpen: () => false }
 		});
 
 		this.toDispose = [