diff --git a/cli/tests/unit/fetch_test.ts b/cli/tests/unit/fetch_test.ts
index 35fe48dca7..204a159a7d 100644
--- a/cli/tests/unit/fetch_test.ts
+++ b/cli/tests/unit/fetch_test.ts
@@ -10,7 +10,7 @@ import {
 } from "./test_util.ts";
 import { Buffer } from "../../../test_util/std/io/buffer.ts";
 
-const listenPort = 4504;
+const listenPort = 4506;
 
 Deno.test(
   { permissions: { net: true } },
@@ -1909,7 +1909,7 @@ Deno.test(
   // https://github.com/denoland/deno/issues/18350
   { ignore: Deno.build.os === "windows", permissions: { net: true } },
   async function fetchRequestBodyErrorCatchable() {
-    const listener = Deno.listen({ hostname: "127.0.0.1", port: 4514 });
+    const listener = Deno.listen({ hostname: "127.0.0.1", port: listenPort });
     const server = (async () => {
       const conn = await listener.accept();
       listener.close();
@@ -1936,7 +1936,7 @@ Deno.test(
     });
 
     const err = await assertRejects(() =>
-      fetch("http://localhost:4514", {
+      fetch(`http://localhost:${listenPort}/`, {
         body: stream,
         method: "POST",
       })
diff --git a/cli/tests/unit/http_test.ts b/cli/tests/unit/http_test.ts
index 549234986b..2e56b1787a 100644
--- a/cli/tests/unit/http_test.ts
+++ b/cli/tests/unit/http_test.ts
@@ -14,6 +14,9 @@ import {
 } from "./test_util.ts";
 import { join } from "../../../test_util/std/path/mod.ts";
 
+const listenPort = 4507;
+const listenPort2 = 4508;
+
 const {
   buildCaseInsensitiveCommaValueFinder,
   // @ts-expect-error TypeScript (as of 3.7) does not support indexing namespaces by symbol
@@ -25,7 +28,7 @@ async function writeRequestAndReadResponse(conn: Deno.Conn): Promise<string> {
 
   const w = new BufWriter(conn);
   const r = new BufReader(conn);
-  const body = `GET / HTTP/1.1\r\nHost: 127.0.0.1:4501\r\n\r\n`;
+  const body = `GET / HTTP/1.1\r\nHost: 127.0.0.1:${listenPort}\r\n\r\n`;
   const writeResult = await w.write(encoder.encode(body));
   assertEquals(body.length, writeResult);
   await w.flush();
@@ -49,21 +52,21 @@ async function writeRequestAndReadResponse(conn: Deno.Conn): Promise<string> {
 Deno.test({ permissions: { net: true } }, async function httpServerBasic() {
   let httpConn: Deno.HttpConn;
   const promise = (async () => {
-    const listener = Deno.listen({ port: 4501 });
+    const listener = Deno.listen({ port: listenPort });
     const conn = await listener.accept();
     listener.close();
     httpConn = Deno.serveHttp(conn);
     const reqEvent = await httpConn.nextRequest();
     assert(reqEvent);
     const { request, respondWith } = reqEvent;
-    assertEquals(new URL(request.url).href, "http://127.0.0.1:4501/");
+    assertEquals(new URL(request.url).href, `http://127.0.0.1:${listenPort}/`);
     assertEquals(await request.text(), "");
     await respondWith(
       new Response("Hello World", { headers: { "foo": "bar" } }),
     );
   })();
 
-  const resp = await fetch("http://127.0.0.1:4501/", {
+  const resp = await fetch(`http://127.0.0.1:${listenPort}/`, {
     headers: { "connection": "close" },
   });
   const clone = resp.clone();
@@ -144,7 +147,7 @@ Deno.test(
   async function httpServerGetRequestBody() {
     let httpConn: Deno.HttpConn;
     const promise = (async () => {
-      const listener = Deno.listen({ port: 4501 });
+      const listener = Deno.listen({ port: listenPort });
       const conn = await listener.accept();
       listener.close();
       httpConn = Deno.serveHttp(conn);
@@ -155,11 +158,11 @@ Deno.test(
       await respondWith(new Response("", { headers: {} }));
     })();
 
-    const conn = await Deno.connect({ port: 4501 });
+    const conn = await Deno.connect({ port: listenPort });
     // Send GET request with a body + content-length.
     const encoder = new TextEncoder();
     const body =
-      `GET / HTTP/1.1\r\nHost: 127.0.0.1:4501\r\nContent-Length: 5\r\n\r\n12345`;
+      `GET / HTTP/1.1\r\nHost: 127.0.0.1:${listenPort}\r\nContent-Length: 5\r\n\r\n12345`;
     const writeResult = await conn.write(encoder.encode(body));
     assertEquals(body.length, writeResult);
 
@@ -184,7 +187,7 @@ Deno.test(
     writer.close();
 
     let httpConn: Deno.HttpConn;
-    const listener = Deno.listen({ port: 4501 });
+    const listener = Deno.listen({ port: listenPort });
     const promise = (async () => {
       const conn = await listener.accept();
       httpConn = Deno.serveHttp(conn);
@@ -195,7 +198,7 @@ Deno.test(
       await respondWith(new Response(stream.readable));
     })();
 
-    const resp = await fetch("http://127.0.0.1:4501/");
+    const resp = await fetch(`http://127.0.0.1:${listenPort}/`);
     const respBody = await resp.text();
     assertEquals("hello world", respBody);
     await promise;
@@ -214,7 +217,7 @@ Deno.test(
     writer.close();
 
     const promise = (async () => {
-      const listener = Deno.listen({ port: 4501 });
+      const listener = Deno.listen({ port: listenPort });
       const conn = await listener.accept();
       const httpConn = Deno.serveHttp(conn);
       const evt = await httpConn.nextRequest();
@@ -225,14 +228,14 @@ Deno.test(
       await respondWith(new Response(""));
 
       // TODO(ry) If we don't call httpConn.nextRequest() here we get "error sending
-      // request for url (https://localhost:4501/): connection closed before
+      // request for url (https://localhost:${listenPort}/): connection closed before
       // message completed".
       assertEquals(await httpConn.nextRequest(), null);
 
       listener.close();
     })();
 
-    const resp = await fetch("http://127.0.0.1:4501/", {
+    const resp = await fetch(`http://127.0.0.1:${listenPort}/`, {
       body: stream.readable,
       method: "POST",
       headers: { "connection": "close" },
@@ -247,7 +250,7 @@ Deno.test(
   { permissions: { net: true } },
   async function httpServerStreamDuplex() {
     let httpConn: Deno.HttpConn;
-    const listener = Deno.listen({ port: 4501 });
+    const listener = Deno.listen({ port: listenPort });
     const promise = (async () => {
       const conn = await listener.accept();
       httpConn = Deno.serveHttp(conn);
@@ -260,7 +263,7 @@ Deno.test(
 
     const ts = new TransformStream();
     const writable = ts.writable.getWriter();
-    const resp = await fetch("http://127.0.0.1:4501/", {
+    const resp = await fetch(`http://127.0.0.1:${listenPort}/`, {
       method: "POST",
       body: ts.readable,
     });
@@ -285,8 +288,8 @@ Deno.test(
 );
 
 Deno.test({ permissions: { net: true } }, async function httpServerClose() {
-  const listener = Deno.listen({ port: 4501 });
-  const client = await Deno.connect({ port: 4501 });
+  const listener = Deno.listen({ port: listenPort });
+  const client = await Deno.connect({ port: listenPort });
   const httpConn = Deno.serveHttp(await listener.accept());
   client.close();
   const evt = await httpConn.nextRequest();
@@ -298,8 +301,8 @@ Deno.test({ permissions: { net: true } }, async function httpServerClose() {
 Deno.test(
   { permissions: { net: true } },
   async function httpServerInvalidMethod() {
-    const listener = Deno.listen({ port: 4501 });
-    const client = await Deno.connect({ port: 4501 });
+    const listener = Deno.listen({ port: listenPort });
+    const client = await Deno.connect({ port: listenPort });
     const httpConn = Deno.serveHttp(await listener.accept());
     await client.write(new Uint8Array([1, 2, 3]));
     await assertRejects(
@@ -319,7 +322,7 @@ Deno.test(
   { permissions: { read: true, net: true } },
   async function httpServerWithTls() {
     const hostname = "localhost";
-    const port = 4501;
+    const port = listenPort;
 
     const promise = (async () => {
       const listener = Deno.listenTls({
@@ -336,7 +339,7 @@ Deno.test(
       await respondWith(new Response("Hello World"));
 
       // TODO(ry) If we don't call httpConn.nextRequest() here we get "error sending
-      // request for url (https://localhost:4501/): connection closed before
+      // request for url (https://localhost:${listenPort}/): connection closed before
       // message completed".
       assertEquals(await httpConn.nextRequest(), null);
 
@@ -360,7 +363,7 @@ Deno.test(
   { permissions: { net: true } },
   async function httpServerRegressionHang() {
     let httpConn: Deno.HttpConn;
-    const listener = Deno.listen({ port: 4501 });
+    const listener = Deno.listen({ port: listenPort });
     const promise = (async () => {
       const conn = await listener.accept();
       httpConn = Deno.serveHttp(conn);
@@ -372,7 +375,7 @@ Deno.test(
       await respondWith(new Response("response"));
     })();
 
-    const resp = await fetch("http://127.0.0.1:4501/", {
+    const resp = await fetch(`http://127.0.0.1:${listenPort}/`, {
       method: "POST",
       body: "request",
     });
@@ -389,7 +392,7 @@ Deno.test(
   { permissions: { net: true } },
   async function httpServerCancelBodyOnResponseFailure() {
     const promise = (async () => {
-      const listener = Deno.listen({ port: 4501 });
+      const listener = Deno.listen({ port: listenPort });
       const conn = await listener.accept();
       const httpConn = Deno.serveHttp(conn);
       const event = await httpConn.nextRequest();
@@ -424,7 +427,7 @@ Deno.test(
       listener.close();
     })();
 
-    const resp = await fetch("http://127.0.0.1:4501/");
+    const resp = await fetch(`http://127.0.0.1:${listenPort}/`);
     await resp.body!.cancel();
     await promise;
   },
@@ -434,7 +437,7 @@ Deno.test(
   { permissions: { net: true } },
   async function httpServerNextRequestErrorExposedInResponse() {
     const promise = (async () => {
-      const listener = Deno.listen({ port: 4501 });
+      const listener = Deno.listen({ port: listenPort });
       const conn = await listener.accept();
       const httpConn = Deno.serveHttp(conn);
       const event = await httpConn.nextRequest();
@@ -469,7 +472,7 @@ Deno.test(
       listener.close();
     })();
 
-    const resp = await fetch("http://127.0.0.1:4501/");
+    const resp = await fetch(`http://127.0.0.1:${listenPort}/`);
     await resp.body!.cancel();
     await promise;
   },
@@ -479,7 +482,7 @@ Deno.test(
   { permissions: { net: true } },
   async function httpServerEmptyBlobResponse() {
     let httpConn: Deno.HttpConn;
-    const listener = Deno.listen({ port: 4501 });
+    const listener = Deno.listen({ port: listenPort });
     const promise = (async () => {
       const conn = await listener.accept();
       httpConn = Deno.serveHttp(conn);
@@ -489,7 +492,7 @@ Deno.test(
       await respondWith(new Response(new Blob([])));
     })();
 
-    const resp = await fetch("http://127.0.0.1:4501/");
+    const resp = await fetch(`http://127.0.0.1:${listenPort}/`);
     const respBody = await resp.text();
     assertEquals("", respBody);
     await promise;
@@ -515,11 +518,11 @@ Deno.test(
       }
     }
 
-    const l = Deno.listen({ port: 4500 });
+    const l = Deno.listen({ port: listenPort });
     serve(l);
 
     await delay(300);
-    const res = await fetch("http://localhost:4500/");
+    const res = await fetch(`http://localhost:${listenPort}/`);
     const _text = await res.text();
 
     // Close connection and listener.
@@ -543,7 +546,7 @@ Deno.test(
     const httpConns: Deno.HttpConn[] = [];
     const promise = (async () => {
       let count = 0;
-      const listener = Deno.listen({ port: 4501 });
+      const listener = Deno.listen({ port: listenPort });
       for await (const conn of listener) {
         (async () => {
           const httpConn = Deno.serveHttp(conn);
@@ -560,7 +563,7 @@ Deno.test(
       }
     })();
 
-    const clientConn = await Deno.connect({ port: 4501 });
+    const clientConn = await Deno.connect({ port: listenPort });
 
     const r1 = await writeRequestAndReadResponse(clientConn);
     assertEquals(r1, "hello");
@@ -600,7 +603,7 @@ Deno.test(
 
       const w = new BufWriter(conn);
       const r = new BufReader(conn);
-      const body = `GET / HTTP/1.1\r\nHost: 127.0.0.1:4501\r\n\r\n`;
+      const body = `GET / HTTP/1.1\r\nHost: 127.0.0.1:${listenPort}\r\n\r\n`;
       const writeResult = await w.write(encoder.encode(body));
       assertEquals(body.length, writeResult);
       await w.flush();
@@ -645,7 +648,7 @@ Deno.test(
     }
 
     let httpConn: Deno.HttpConn;
-    const listener = Deno.listen({ port: 4501 });
+    const listener = Deno.listen({ port: listenPort });
     const finished = (async () => {
       const conn = await listener.accept();
       httpConn = Deno.serveHttp(conn);
@@ -655,7 +658,7 @@ Deno.test(
     })();
 
     // start a client
-    const clientConn = await Deno.connect({ port: 4501 });
+    const clientConn = await Deno.connect({ port: listenPort });
 
     const r1 = await writeRequest(clientConn);
     assertEquals(r1, "0\n1\n2\n");
@@ -673,7 +676,7 @@ Deno.test(
   async function httpRequestLatin1Headers() {
     let httpConn: Deno.HttpConn;
     const promise = (async () => {
-      const listener = Deno.listen({ port: 4501 });
+      const listener = Deno.listen({ port: listenPort });
       const conn = await listener.accept();
       listener.close();
       httpConn = Deno.serveHttp(conn);
@@ -686,9 +689,9 @@ Deno.test(
       );
     })();
 
-    const clientConn = await Deno.connect({ port: 4501 });
+    const clientConn = await Deno.connect({ port: listenPort });
     const requestText =
-      "GET / HTTP/1.1\r\nHost: 127.0.0.1:4501\r\nX-Header-Test: á\r\n\r\n";
+      `GET / HTTP/1.1\r\nHost: 127.0.0.1:${listenPort}\r\nX-Header-Test: á\r\n\r\n`;
     const requestBytes = new Uint8Array(requestText.length);
     for (let i = 0; i < requestText.length; i++) {
       requestBytes[i] = requestText.charCodeAt(i);
@@ -721,7 +724,7 @@ Deno.test(
   { permissions: { net: true } },
   async function httpServerRequestWithoutPath() {
     let httpConn: Deno.HttpConn;
-    const listener = Deno.listen({ port: 4501 });
+    const listener = Deno.listen({ port: listenPort });
     const promise = (async () => {
       const conn = await listener.accept();
       listener.close();
@@ -729,12 +732,15 @@ Deno.test(
       const reqEvent = await httpConn.nextRequest();
       assert(reqEvent);
       const { request, respondWith } = reqEvent;
-      assertEquals(new URL(request.url).href, "http://127.0.0.1:4501/");
+      assertEquals(
+        new URL(request.url).href,
+        `http://127.0.0.1:${listenPort}/`,
+      );
       assertEquals(await request.text(), "");
       await respondWith(new Response());
     })();
 
-    const clientConn = await Deno.connect({ port: 4501 });
+    const clientConn = await Deno.connect({ port: listenPort });
 
     async function writeRequest(conn: Deno.Conn) {
       const encoder = new TextEncoder();
@@ -742,7 +748,7 @@ Deno.test(
       const w = new BufWriter(conn);
       const r = new BufReader(conn);
       const body =
-        `CONNECT 127.0.0.1:4501 HTTP/1.1\r\nHost: 127.0.0.1:4501\r\n\r\n`;
+        `CONNECT 127.0.0.1:${listenPort} HTTP/1.1\r\nHost: 127.0.0.1:${listenPort}\r\n\r\n`;
       const writeResult = await w.write(encoder.encode(body));
       assertEquals(body.length, writeResult);
       await w.flush();
@@ -766,7 +772,7 @@ Deno.test(
 
 Deno.test({ permissions: { net: true } }, async function httpServerWebSocket() {
   const promise = (async () => {
-    const listener = Deno.listen({ port: 4501 });
+    const listener = Deno.listen({ port: listenPort });
     const conn = await listener.accept();
     listener.close();
     const httpConn = Deno.serveHttp(conn);
@@ -786,7 +792,7 @@ Deno.test({ permissions: { net: true } }, async function httpServerWebSocket() {
   })();
 
   const def = deferred();
-  const ws = new WebSocket("ws://localhost:4501");
+  const ws = new WebSocket(`ws://localhost:${listenPort}`);
   ws.onmessage = (m) => assertEquals(m.data, "foo");
   ws.onerror = () => fail();
   ws.onclose = () => def.resolve();
@@ -887,20 +893,23 @@ Deno.test(
   async function httpCookieConcatenation() {
     let httpConn: Deno.HttpConn;
     const promise = (async () => {
-      const listener = Deno.listen({ port: 4501 });
+      const listener = Deno.listen({ port: listenPort });
       const conn = await listener.accept();
       listener.close();
       httpConn = Deno.serveHttp(conn);
       const reqEvent = await httpConn.nextRequest();
       assert(reqEvent);
       const { request, respondWith } = reqEvent;
-      assertEquals(new URL(request.url).href, "http://127.0.0.1:4501/");
+      assertEquals(
+        new URL(request.url).href,
+        `http://127.0.0.1:${listenPort}/`,
+      );
       assertEquals(await request.text(), "");
       assertEquals(request.headers.get("cookie"), "foo=bar; bar=foo");
       await respondWith(new Response("ok"));
     })();
 
-    const resp = await fetch("http://127.0.0.1:4501/", {
+    const resp = await fetch(`http://127.0.0.1:${listenPort}/`, {
       headers: [
         ["connection", "close"],
         ["cookie", "foo=bar"],
@@ -916,8 +925,8 @@ Deno.test(
 
 // https://github.com/denoland/deno/issues/11651
 Deno.test({ permissions: { net: true } }, async function httpServerPanic() {
-  const listener = Deno.listen({ port: 4501 });
-  const client = await Deno.connect({ port: 4501 });
+  const listener = Deno.listen({ port: listenPort });
+  const client = await Deno.connect({ port: listenPort });
   const conn = await listener.accept();
   const httpConn = Deno.serveHttp(conn);
 
@@ -943,7 +952,7 @@ Deno.test(
     file.close();
 
     let httpConn: Deno.HttpConn;
-    const listener = Deno.listen({ port: 4501 });
+    const listener = Deno.listen({ port: listenPort });
     const promise = (async () => {
       const conn = await listener.accept();
       httpConn = Deno.serveHttp(conn);
@@ -952,7 +961,7 @@ Deno.test(
       const f = await Deno.open(tmpFile, { read: true });
       await respondWith(new Response(f.readable, { status: 200 }));
     })();
-    const resp = await fetch("http://127.0.0.1:4501/");
+    const resp = await fetch(`http://127.0.0.1:${listenPort}/`);
     const body = await resp.arrayBuffer();
     assertEquals(body.byteLength, 70 * 1024);
     await promise;
@@ -964,9 +973,9 @@ Deno.test(
 Deno.test(
   { permissions: { net: true, write: true, read: true } },
   async function httpServerClosedStream() {
-    const listener = Deno.listen({ port: 4502 });
+    const listener = Deno.listen({ port: listenPort });
 
-    const client = await Deno.connect({ port: 4502 });
+    const client = await Deno.connect({ port: listenPort });
     await client.write(new TextEncoder().encode(
       `GET / HTTP/1.0\r\n\r\n`,
     ));
@@ -1006,9 +1015,9 @@ Deno.test(
 Deno.test(
   { permissions: { net: true } },
   async function httpServerIncompleteMessage() {
-    const listener = Deno.listen({ port: 4501 });
+    const listener = Deno.listen({ port: listenPort });
 
-    const client = await Deno.connect({ port: 4501 });
+    const client = await Deno.connect({ port: listenPort });
     await client.write(new TextEncoder().encode(
       `GET / HTTP/1.0\r\n\r\n`,
     ));
@@ -1053,17 +1062,17 @@ Deno.test(
 Deno.test(
   { permissions: { net: true } },
   async function httpServerDoesntLeakResources() {
-    const listener = Deno.listen({ port: 4505 });
+    const listener = Deno.listen({ port: listenPort });
     const [conn, clientConn] = await Promise.all([
       listener.accept(),
-      Deno.connect({ port: 4505 }),
+      Deno.connect({ port: listenPort }),
     ]);
     const httpConn = Deno.serveHttp(conn);
 
     await Promise.all([
       httpConn.nextRequest(),
       clientConn.write(new TextEncoder().encode(
-        `GET / HTTP/1.1\r\nHost: 127.0.0.1:4505\r\n\r\n`,
+        `GET / HTTP/1.1\r\nHost: 127.0.0.1:${listenPort}\r\n\r\n`,
       )),
     ]);
 
@@ -1081,11 +1090,14 @@ Deno.test(
     let httpConn: Deno.HttpConn;
 
     const promise = (async () => {
-      listener = Deno.listen({ port: 4508 });
+      listener = Deno.listen({ port: listenPort });
       for await (const conn of listener) {
         httpConn = Deno.serveHttp(conn);
         for await (const { request, respondWith } of httpConn) {
-          assertEquals(new URL(request.url).href, "http://127.0.0.1:4508/");
+          assertEquals(
+            new URL(request.url).href,
+            `http://127.0.0.1:${listenPort}/`,
+          );
           // not reading request body on purpose
           respondWith(new Response("ok"));
         }
@@ -1093,7 +1105,7 @@ Deno.test(
     })();
 
     const resourcesBefore = Deno.resources();
-    const response = await fetch("http://127.0.0.1:4508", {
+    const response = await fetch(`http://127.0.0.1:${listenPort}`, {
       method: "POST",
       body: "hello world",
     });
@@ -1151,7 +1163,7 @@ Deno.test(
   { permissions: { net: true } },
   async function httpConnConcurrentNextRequestCalls() {
     const hostname = "localhost";
-    const port = 4501;
+    const port = listenPort;
 
     let httpConn: Deno.HttpConn;
     const listener = Deno.listen({ hostname, port });
@@ -1189,7 +1201,7 @@ Deno.test(
   { permissions: { net: true } },
   async function httpConnAutoCloseDelayedOnUpgrade() {
     const hostname = "localhost";
-    const port = 4501;
+    const port = listenPort;
 
     async function server() {
       const listener = Deno.listen({ hostname, port });
@@ -1234,7 +1246,7 @@ Deno.test(
   { permissions: { net: true, run: true } },
   async function httpServerDeleteRequestHasBody() {
     const hostname = "localhost";
-    const port = 4501;
+    const port = listenPort;
 
     let httpConn: Deno.HttpConn;
     const listener = Deno.listen({ hostname, port });
@@ -1268,7 +1280,7 @@ Deno.test(
   { permissions: { net: true } },
   async function httpServerRespondNonAsciiUint8Array() {
     let httpConn: Deno.HttpConn;
-    const listener = Deno.listen({ port: 4501 });
+    const listener = Deno.listen({ port: listenPort });
     const promise = (async () => {
       const conn = await listener.accept();
       listener.close();
@@ -1282,7 +1294,7 @@ Deno.test(
       );
     })();
 
-    const resp = await fetch("http://localhost:4501/");
+    const resp = await fetch(`http://localhost:${listenPort}/`);
     assertEquals(resp.status, 200);
     const body = await resp.arrayBuffer();
     assertEquals(new Uint8Array(body), new Uint8Array([128]));
@@ -1350,7 +1362,7 @@ Deno.test({
   permissions: { net: true, run: true },
   async fn() {
     const hostname = "localhost";
-    const port = 4501;
+    const port = listenPort;
     const listener = Deno.listen({ hostname, port });
 
     const data = { hello: "deno", now: "with", compressed: "body" };
@@ -1402,7 +1414,7 @@ Deno.test({
   permissions: { net: true, run: true },
   async fn() {
     const hostname = "localhost";
-    const port = 4501;
+    const port = listenPort;
     const listener = Deno.listen({ hostname, port });
 
     const data = { hello: "deno", now: "with", compressed: "body" };
@@ -1459,7 +1471,7 @@ Deno.test({
   permissions: { net: true, run: true },
   async fn() {
     const hostname = "localhost";
-    const port = 4501;
+    const port = listenPort;
 
     let httpConn: Deno.HttpConn;
     async function server() {
@@ -1512,7 +1524,7 @@ Deno.test({
   permissions: { net: true, run: true },
   async fn() {
     const hostname = "localhost";
-    const port = 4501;
+    const port = listenPort;
 
     let httpConn: Deno.HttpConn;
     async function server() {
@@ -1568,7 +1580,7 @@ Deno.test({
   permissions: { net: true, run: true },
   async fn() {
     const hostname = "localhost";
-    const port = 4501;
+    const port = listenPort;
 
     let httpConn: Deno.HttpConn;
     async function server() {
@@ -1621,7 +1633,7 @@ Deno.test({
   permissions: { net: true, run: true },
   async fn() {
     const hostname = "localhost";
-    const port = 4501;
+    const port = listenPort;
 
     let httpConn: Deno.HttpConn;
     async function server() {
@@ -1681,7 +1693,7 @@ Deno.test({
   permissions: { net: true, run: true },
   async fn() {
     const hostname = "localhost";
-    const port = 4501;
+    const port = listenPort;
 
     let httpConn: Deno.HttpConn;
     async function server() {
@@ -1740,7 +1752,7 @@ Deno.test({
   permissions: { net: true, run: true },
   async fn() {
     const hostname = "localhost";
-    const port = 4501;
+    const port = listenPort;
 
     let httpConn: Deno.HttpConn;
     async function server() {
@@ -1796,7 +1808,7 @@ Deno.test({
   permissions: { net: true, run: true },
   async fn() {
     const hostname = "localhost";
-    const port = 4501;
+    const port = listenPort;
 
     let httpConn: Deno.HttpConn;
     async function server() {
@@ -1852,7 +1864,7 @@ Deno.test({
   permissions: { net: true, run: true },
   async fn() {
     const hostname = "localhost";
-    const port = 4501;
+    const port = listenPort;
 
     const encoder = new TextEncoder();
     const listener = Deno.listen({ hostname, port });
@@ -1914,7 +1926,7 @@ Deno.test({
   permissions: { net: true, run: true },
   async fn() {
     const hostname = "localhost";
-    const port = 4501;
+    const port = listenPort;
 
     const encoder = new TextEncoder();
     const listener = Deno.listen({ hostname, port });
@@ -1980,7 +1992,7 @@ Deno.test({
   permissions: { net: true, run: true },
   async fn() {
     const hostname = "localhost";
-    const port = 4501;
+    const port = listenPort;
     let contentLength: string;
 
     let httpConn: Deno.HttpConn;
@@ -2046,7 +2058,7 @@ Deno.test({
   permissions: { net: true, run: true },
   async fn() {
     const hostname = "localhost";
-    const port = 4501;
+    const port = listenPort;
     let contentLength: string;
 
     let httpConn: Deno.HttpConn;
@@ -2108,7 +2120,7 @@ Deno.test({
   permissions: { net: true, run: true },
   async fn() {
     const hostname = "localhost";
-    const port = 4501;
+    const port = listenPort;
     let contentLength: string;
 
     let httpConn: Deno.HttpConn;
@@ -2165,7 +2177,7 @@ Deno.test({
 
 Deno.test("upgradeHttp tcp", async () => {
   async function client() {
-    const tcpConn = await Deno.connect({ port: 4501 });
+    const tcpConn = await Deno.connect({ port: listenPort });
     await tcpConn.write(
       new TextEncoder().encode(
         "CONNECT server.example.com:80 HTTP/1.1\r\n\r\nbla bla bla\nbla bla\nbla\n",
@@ -2201,7 +2213,7 @@ Deno.test("upgradeHttp tcp", async () => {
     })();
 
     return new Response(null, { status: 101 });
-  }, { port: 4501, signal });
+  }, { port: listenPort, signal });
 
   await Promise.all([server, client()]);
 });
@@ -2216,7 +2228,7 @@ Deno.test(
       ];
       const tlsConn = await Deno.connectTls({
         hostname: "localhost",
-        port: 4502,
+        port: listenPort,
         caCerts,
       });
       await tlsConn.write(
@@ -2256,7 +2268,7 @@ Deno.test(
       })();
 
       return new Response(null, { status: 101 });
-    }, { hostname: "localhost", port: 4502, signal, keyFile, certFile });
+    }, { hostname: "localhost", port: listenPort, signal, keyFile, certFile });
 
     await Promise.all([server, client()]);
   },
@@ -2329,7 +2341,7 @@ Deno.test(
 
     let httpConn: Deno.HttpConn;
     const promise = (async () => {
-      const listener = Deno.listen({ port: 4501 });
+      const listener = Deno.listen({ port: listenPort });
       const conn = await listener.accept();
       listener.close();
       httpConn = Deno.serveHttp(conn);
@@ -2340,7 +2352,7 @@ Deno.test(
       await respondWith(new Response(body));
     })();
 
-    const resp = await fetch("http://127.0.0.1:4501/", {
+    const resp = await fetch(`http://127.0.0.1:${listenPort}/`, {
       method: "POST",
       headers: { "connection": "close" },
       body,
@@ -2376,7 +2388,7 @@ Deno.test(
 
     let httpConn: Deno.HttpConn;
     const promise = (async () => {
-      const listener = Deno.listen({ port: 4501 });
+      const listener = Deno.listen({ port: listenPort });
       const conn = await listener.accept();
       listener.close();
       httpConn = Deno.serveHttp(conn);
@@ -2387,7 +2399,7 @@ Deno.test(
       await respondWith(new Response(body));
     })();
 
-    const resp = await fetch("http://127.0.0.1:4501/", {
+    const resp = await fetch(`http://127.0.0.1:${listenPort}/`, {
       method: "POST",
       headers: { "connection": "close" },
       body: stream.readable,
@@ -2405,7 +2417,7 @@ Deno.test(
     permissions: { net: true },
   },
   async function httpServerWithoutExclusiveAccessToTcp() {
-    const port = 4506;
+    const port = listenPort;
     const listener = Deno.listen({ port });
 
     const [clientConn, serverConn] = await Promise.all([
@@ -2429,7 +2441,7 @@ Deno.test(
   },
   async function httpServerWithoutExclusiveAccessToTls() {
     const hostname = "localhost";
-    const port = 4507;
+    const port = listenPort;
     const listener = Deno.listenTls({
       hostname,
       port,
@@ -2485,7 +2497,7 @@ Deno.test(
   async function httpServerRequestResponseClone() {
     const body = "deno".repeat(64 * 1024);
     let httpConn: Deno.HttpConn;
-    const listener = Deno.listen({ port: 4501 });
+    const listener = Deno.listen({ port: listenPort });
     const promise = (async () => {
       const conn = await listener.accept();
       listener.close();
@@ -2524,7 +2536,7 @@ Deno.test(
       await respondWith(new Response(body));
     })();
 
-    const response = await fetch("http://localhost:4501", {
+    const response = await fetch(`http://localhost:${listenPort}`, {
       body,
       method: "POST",
     });
@@ -2541,8 +2553,8 @@ Deno.test({
   permissions: { net: true, run: true },
   async fn() {
     const hostname = "localhost";
-    const port = 4501;
-    const port2 = 4502;
+    const port = listenPort;
+    const port2 = listenPort2;
 
     const encoder = new TextEncoder();
     const listener = Deno.listen({ hostname, port });
@@ -2674,7 +2686,7 @@ for (const compression of [true, false]) {
     permissions: { net: true },
     async fn() {
       const hostname = "localhost";
-      const port = 4501;
+      const port = listenPort;
 
       const listener = Deno.listen({ hostname, port });
       const server = httpServerWithErrorBody(listener, compression);
@@ -2707,7 +2719,7 @@ for (const compression of [true, false]) {
     permissions: { net: true },
     async fn() {
       const hostname = "localhost";
-      const port = 4501;
+      const port = listenPort;
 
       const listener = Deno.listen({ hostname, port });
       const server = httpServerWithErrorBody(listener, compression);
@@ -2734,7 +2746,7 @@ for (const compression of [true, false]) {
     permissions: { net: true, read: true },
     async fn() {
       const hostname = "localhost";
-      const port = 4501;
+      const port = listenPort;
 
       const listener = Deno.listenTls({
         hostname,
@@ -2770,7 +2782,7 @@ Deno.test({
   async fn() {
     let httpConn: Deno.HttpConn;
     const promise = (async () => {
-      const listener = Deno.listen({ port: 4501 });
+      const listener = Deno.listen({ port: listenPort });
       const conn = await listener.accept();
       listener.close();
       httpConn = Deno.serveHttp(conn);
@@ -2784,7 +2796,7 @@ Deno.test({
 
     const abortController = new AbortController();
 
-    fetch("http://127.0.0.1:4501/", {
+    fetch(`http://127.0.0.1:${listenPort}/`, {
       signal: abortController.signal,
     }).catch(() => {
       // ignore