diff --git a/src/vs/workbench/api/common/extHostTypeConverters.ts b/src/vs/workbench/api/common/extHostTypeConverters.ts
index c998bd2c5f88c2b53d540bdddacb335aa2c84837..6027377e166dc7847ed35306b84d32aa82695109 100644
--- a/src/vs/workbench/api/common/extHostTypeConverters.ts
+++ b/src/vs/workbench/api/common/extHostTypeConverters.ts
@@ -257,7 +257,7 @@ export namespace MarkdownString {
 		} else if (htmlContent.isMarkdownString(markup)) {
 			res = markup;
 		} else if (typeof markup === 'string') {
-			res = { value: <string>markup };
+			res = { value: markup };
 		} else {
 			res = { value: '' };
 		}