diff --git a/src/vs/languages/typescript/common/features/diagnostics.ts b/src/vs/languages/typescript/common/features/diagnostics.ts
index fc7ae9e26d5274c1dfe383018222abc5328f99f3..e4691e3bc87531d8db1ee03ac1152c79dcd2204e 100644
--- a/src/vs/languages/typescript/common/features/diagnostics.ts
+++ b/src/vs/languages/typescript/common/features/diagnostics.ts
@@ -129,7 +129,6 @@ function _asMarker(diagnostic: ts.Diagnostic, classifier: DiagnosticClassifier,
 	markers.push({
 		severity,
 		message: ts.flattenDiagnosticMessageText(diagnostic.messageText, '\n'),
-		source: 'JavaScript',
 		code: diagnostic.code.toString(),
 		startLineNumber: range.startLineNumber,
 		startColumn: range.startColumn,