diff --git a/src/vs/editor/contrib/documentSymbols/outlineModel.ts b/src/vs/editor/contrib/documentSymbols/outlineModel.ts
index ff7caa8d0ee49341fcd910e019ad318f05cae5d8..cb26e950de1087e6f9650114dae890ed1a8741c7 100644
--- a/src/vs/editor/contrib/documentSymbols/outlineModel.ts
+++ b/src/vs/editor/contrib/documentSymbols/outlineModel.ts
@@ -361,14 +361,17 @@ export class OutlineModel extends TreeElement {
 	}
 
 	private _compact(): this {
+		let count = 0;
 		for (const key in this._groups) {
 			let group = this._groups[key];
 			if (first(group.children) === undefined) { // empty
 				delete this._groups[key];
+			} else {
+				count += 1;
 			}
 		}
 		let group = first(this._groups);
-		if (group) {
+		if (group && count === 1) {
 			// adopt all elements of the first group
 			for (let key in group.children) {
 				let child = group.children[key];