diff --git a/CLAUDE.md b/CLAUDE.md
index 741135c56..cd44bbcec 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -106,7 +106,6 @@ npm run generate-types
 
 ```sh
 ./scripts/install-binaries
-npm run build:http
 ```
 
 ## Backend architecture
diff --git a/tests/support/globalSetup.ts b/tests/support/globalSetup.ts
index 2faacc67a..620a3474c 100644
--- a/tests/support/globalSetup.ts
+++ b/tests/support/globalSetup.ts
@@ -14,6 +14,7 @@ import {
   removeWorkspace,
   tmpDir,
 } from "@tests/support/support.js";
+import { execa } from "execa";
 
 const heartwoodBinaryPath = Path.join(
   tmpDir,
@@ -43,6 +44,13 @@ export default async function globalSetup(): Promise<() => void> {
     await removeWorkspace();
   }
 
+  console.log("Building test-http-api");
+  await execa("cargo", [
+    "build",
+    "--manifest-path",
+    "./crates/test-http-api/Cargo.toml",
+  ]);
+
   const peerManager = await createPeerManager({
     dataDir: Path.resolve(tmpDir, "peers"),
     outputLog: Fs.createWriteStream(
@@ -67,7 +75,6 @@ export default async function globalSetup(): Promise<() => void> {
         alias: "palm",
       },
     });
-    await palm.startHttpd(parseInt(process.env.VITE_TEST_HTTP_API_PORT ?? "0"));
 
     try {
       console.log("Creating markdown fixture");
@@ -85,9 +92,8 @@ export default async function globalSetup(): Promise<() => void> {
       process.exit(1);
     }
     await palm.stopNode();
-  } else {
-    await palm.startHttpd(parseInt(process.env.VITE_TEST_HTTP_API_PORT ?? "0"));
   }
+  await palm.startHttpd(parseInt(process.env.VITE_TEST_HTTP_API_PORT ?? "0"));
 
   return async () => {
     await peerManager.shutdown();
diff --git a/tests/support/peerManager.ts b/tests/support/peerManager.ts
index 5ac4e4ca1..0223cf3ae 100644
--- a/tests/support/peerManager.ts
+++ b/tests/support/peerManager.ts
@@ -9,7 +9,7 @@ import * as Util from "node:util";
 
 import { type Config, defaultConfig } from "@tests/support/fixtures.js";
 import { logPrefix } from "@tests/support/logPrefix.js";
-import { randomTag } from "@tests/support/support.js";
+import { randomTag, testHttpApiBinary } from "@tests/support/support.js";
 import { execa } from "execa";
 import getPort from "get-port";
 import matches from "lodash/matches.js";
@@ -251,30 +251,20 @@ export class RadiclePeer {
     await this.spawn("rad", ["auth"]);
   }
 
+  // Without a port the OS picks a free one, which the server reports back.
+  // Choosing one up front raced between workers: the second server failed to
+  // bind, and its page talked to the other worker's server instead.
   public async startHttpd(port?: number): Promise<void> {
-    if (!port) {
-      port = await getPort();
-    }
-    this.#httpdBaseUrl = {
-      hostname: "127.0.0.1",
-      port,
-      scheme: "http",
-    };
-    void this.spawn("cargo", [
-      "run",
-      "--manifest-path",
-      "./crates/test-http-api/Cargo.toml",
-      "--",
+    const httpd = this.spawn(testHttpApiBinary, [
       "--listen",
-      `${this.#httpdBaseUrl.hostname}:${this.#httpdBaseUrl.port}`,
+      `127.0.0.1:${port ?? 0}`,
     ]);
-
-    await waitOn({
-      resources: [
-        `tcp:${this.#httpdBaseUrl.hostname}:${this.#httpdBaseUrl.port}`,
-      ],
-      timeout: 120_000,
-    });
+    if (port) {
+      await waitOn({ resources: [`tcp:127.0.0.1:${port}`], timeout: 10_000 });
+    } else {
+      port = await reportedPort(httpd);
+    }
+    this.#httpdBaseUrl = { hostname: "127.0.0.1", port, scheme: "http" };
   }
 
   public async startNode(config: Partial<Config> = defaultConfig) {
@@ -444,3 +434,29 @@ async function updateConfig(radHome: string, configParams: Partial<Config>) {
   };
   await Fs.writeFile(configPath, JSON.stringify(config), "utf-8");
 }
+
+async function reportedPort(httpd: SpawnResult): Promise<number> {
+  if (!httpd.stdout) {
+    throw new Error("test-http-api has no stdout to read its port from");
+  }
+  const lines = readline.createInterface({ input: httpd.stdout });
+  const exited = httpd.then(
+    () => {
+      throw new Error("test-http-api exited before it was listening");
+    },
+    (error: unknown) => {
+      throw error;
+    },
+  );
+  const listening = (async () => {
+    for await (const line of lines) {
+      const match = /^listening on .*:(\d+)$/.exec(line);
+      if (match) {
+        lines.close();
+        return Number(match[1]);
+      }
+    }
+    throw new Error("test-http-api closed its output before it was listening");
+  })();
+  return Promise.race([listening, exited]);
+}
diff --git a/tests/support/support.ts b/tests/support/support.ts
index 85608f47a..b951f0a31 100644
--- a/tests/support/support.ts
+++ b/tests/support/support.ts
@@ -24,6 +24,13 @@ const filename = fileURLToPath(import.meta.url);
 export const supportDir = Path.dirname(filename);
 export const tmpDir = Path.resolve(supportDir, "..", "./tmp");
 export const fixturesDir = Path.resolve(supportDir, "..", "./fixtures");
+export const testHttpApiBinary = Path.resolve(
+  supportDir,
+  "../..",
+  process.env.CARGO_TARGET_DIR ?? "target",
+  "debug",
+  "test-http-api",
+);
 const workspacePaths = [Path.join(tmpDir, "peers"), Path.join(tmpDir, "repos")];
 
 export const heartwoodRelease = (