diff --git a/src/server/protocol.ts b/src/server/protocol.ts
index d398555408b..8a75311c5d1 100644
--- a/src/server/protocol.ts
+++ b/src/server/protocol.ts
@@ -2416,8 +2416,8 @@ namespace ts.server.protocol {
     }
 
     export const enum NewLineKind {
-        Crlf,
-        Lf,
+        Crlf = "Crlf",
+        Lf = "Lf",
     }
 
     export const enum ScriptTarget {