diff --git a/src/vs/workbench/api/common/extHostUriOpener.ts b/src/vs/workbench/api/common/extHostUriOpener.ts
index 271330e5c10..033dc90a423 100644
--- a/src/vs/workbench/api/common/extHostUriOpener.ts
+++ b/src/vs/workbench/api/common/extHostUriOpener.ts
@@ -41,7 +41,7 @@ export class ExtHostUriOpeners implements ExtHostUriOpenersShape {
 		const handle = ExtHostUriOpeners.HandlePool++;
 
 		this._openers.set(handle, { opener, schemes: new Set(schemes) });
-		this._proxy.$registerUriOpener(handle);
+		this._proxy.$registerUriOpener(handle, schemes);
 
 		return toDisposable(() => {
 			this._openers.delete(handle);