diff --git a/src/tsserver/webServer.ts b/src/tsserver/webServer.ts
index 704fd3d2887b4..18d9ab4d13e97 100644
--- a/src/tsserver/webServer.ts
+++ b/src/tsserver/webServer.ts
@@ -1,8 +1,12 @@
 /*@internal*/
-
-/// <reference lib="webworker" />
-
 namespace ts.server {
+    declare const addEventListener: any;
+    declare const postMessage: any;
+    declare const close: any;
+    declare const location: any;
+    declare const XMLHttpRequest: any;
+    declare const self: any;
+
     const nullLogger: Logger = {
         close: noop,
         hasLevel: returnFalse,
@@ -82,7 +86,7 @@ namespace ts.server {
     }
 
     function hrtime(previous?: [number, number]) {
-        const now = self.performance.now() * 1e-3;
+        const now = self.performance.now(performance) * 1e-3;
         let seconds = Math.floor(now);
         let nanoseconds = Math.floor((now % 1) * 1e9);
         if (previous) {
@@ -105,7 +109,7 @@ namespace ts.server {
             exit() {
                 this.logger.info("Exiting...");
                 this.projectService.closeLog();
-                close();
+                close(0);
             }
 
             listen() {