diff --git a/src/vs/base/browser/ui/splitview/splitview.ts b/src/vs/base/browser/ui/splitview/splitview.ts
index e00230f4abb274027b709a0bbf71643d6e028436..863623a8c0d4d3f18bdcbf0e65c48906b05255a6 100644
--- a/src/vs/base/browser/ui/splitview/splitview.ts
+++ b/src/vs/base/browser/ui/splitview/splitview.ts
@@ -689,7 +689,7 @@ export class SplitView<TLayoutContext = undefined> extends Disposable {
 
 		// Add sash
 		if (this.viewItems.length > 1) {
-			const sash = this.orientation === Orientation.HORIZONTAL
+			const sash = this.orientation === Orientation.VERTICAL
 				? new Sash(this.sashContainer, { getHorizontalSashTop: (sash: Sash) => this.getSashPosition(sash) }, {
 					orientation: Orientation.HORIZONTAL,
 					orthogonalStartSash: this.orthogonalStartSash,