diff --git a/src/harness/tsconfig.json b/src/harness/tsconfig.json
index 4fded517e19..d752c0f235b 100644
--- a/src/harness/tsconfig.json
+++ b/src/harness/tsconfig.json
@@ -96,7 +96,7 @@
         "rwcRunner.ts",
         "test262Runner.ts",
         "runner.ts",
-        "../server/protocol.d.ts",
+        "../server/protocol.ts",
         "../server/session.ts",
         "../server/client.ts",
         "../server/editorServices.ts",