diff --git a/dist/main/index.js b/dist/main/index.js
index a586e38..ead724f 100644
--- a/dist/main/index.js
+++ b/dist/main/index.js
@@ -69877,6 +69877,43 @@ function requireEnv(name) {
   return value;
 }
 
+// src/retry.ts
+var TransientError = class extends Error {
+  name = "TransientError";
+};
+function isTransient(err) {
+  if (err instanceof TransientError) return true;
+  if (!(err instanceof Error)) return false;
+  if (err.name === "AbortError" || err.name === "TimeoutError") return true;
+  const msg = err.message;
+  const http_match = /HTTP\D+(\d{3})/i.exec(msg);
+  if (http_match) {
+    const code = Number(http_match[1]);
+    return code >= 500 && code < 600;
+  }
+  return /ECONNRESET|ETIMEDOUT|EAI_AGAIN|ENOTFOUND|ECONNREFUSED|socket hang up/i.test(msg);
+}
+async function withRetry(fn, opts = {}) {
+  const retries = opts.retries ?? 1;
+  const min_delay = opts.minDelayMs ?? 500;
+  const jitter = opts.jitterMs ?? 500;
+  const classify = opts.isTransient ?? isTransient;
+  const sleep2 = opts.sleep ?? defaultSleep;
+  let attempt = 0;
+  for (; ; ) {
+    try {
+      return await fn();
+    } catch (err) {
+      if (attempt >= retries || !classify(err)) throw err;
+      attempt++;
+      await sleep2(min_delay + Math.floor(Math.random() * jitter));
+    }
+  }
+}
+function defaultSleep(ms) {
+  return new Promise((r) => setTimeout(r, ms));
+}
+
 // src/common.ts
 var VERSIONS_JSON = "https://ziglang.org/download/index.json";
 var MACH_VERSIONS_JSON = "https://pkg.machengine.org/zig/index.json";
@@ -69970,11 +70007,13 @@ function compareReleaseParts(a, b) {
   return a[0] - b[0] || a[1] - b[1] || a[2] - b[2];
 }
 async function fetchJsonWithTimeout(url2, timeout_ms) {
-  const resp = await fetch(url2, { signal: AbortSignal.timeout(timeout_ms) });
-  if (!resp.ok) {
-    throw new Error(`Fetch ${url2} failed: HTTP ${resp.status}`);
-  }
-  return await resp.json();
+  return await withRetry(async () => {
+    const resp = await fetch(url2, { signal: AbortSignal.timeout(timeout_ms) });
+    if (!resp.ok) {
+      throw new Error(`Fetch ${url2} failed: HTTP ${resp.status}`);
+    }
+    return await resp.json();
+  });
 }
 async function getTarballName() {
   const version3 = await getVersion2();
@@ -70196,43 +70235,6 @@ async function runAttempt(item, thunk, log2) {
   }
 }
 
-// src/retry.ts
-var TransientError = class extends Error {
-  name = "TransientError";
-};
-function isTransient(err) {
-  if (err instanceof TransientError) return true;
-  if (!(err instanceof Error)) return false;
-  if (err.name === "AbortError") return true;
-  const msg = err.message;
-  const http_match = /HTTP\D+(\d{3})/i.exec(msg);
-  if (http_match) {
-    const code = Number(http_match[1]);
-    return code >= 500 && code < 600;
-  }
-  return /ECONNRESET|ETIMEDOUT|EAI_AGAIN|ENOTFOUND|ECONNREFUSED|socket hang up/i.test(msg);
-}
-async function withRetry(fn, opts = {}) {
-  const retries = opts.retries ?? 1;
-  const min_delay = opts.minDelayMs ?? 500;
-  const jitter = opts.jitterMs ?? 500;
-  const classify = opts.isTransient ?? isTransient;
-  const sleep2 = opts.sleep ?? defaultSleep;
-  let attempt = 0;
-  for (; ; ) {
-    try {
-      return await fn();
-    } catch (err) {
-      if (attempt >= retries || !classify(err)) throw err;
-      attempt++;
-      await sleep2(min_delay + Math.floor(Math.random() * jitter));
-    }
-  }
-}
-function defaultSleep(ms) {
-  return new Promise((r) => setTimeout(r, ms));
-}
-
 // src/source-tag.ts
 function withSource(url2, tag) {
   if (!tag) return url2;
diff --git a/dist/post/index.js b/dist/post/index.js
index 5deeff1..37a4d4f 100644
--- a/dist/post/index.js
+++ b/dist/post/index.js
@@ -68725,6 +68725,43 @@ function errMessage(err) {
   }
 }
 
+// src/retry.ts
+var TransientError = class extends Error {
+  name = "TransientError";
+};
+function isTransient(err) {
+  if (err instanceof TransientError) return true;
+  if (!(err instanceof Error)) return false;
+  if (err.name === "AbortError" || err.name === "TimeoutError") return true;
+  const msg = err.message;
+  const http_match = /HTTP\D+(\d{3})/i.exec(msg);
+  if (http_match) {
+    const code = Number(http_match[1]);
+    return code >= 500 && code < 600;
+  }
+  return /ECONNRESET|ETIMEDOUT|EAI_AGAIN|ENOTFOUND|ECONNREFUSED|socket hang up/i.test(msg);
+}
+async function withRetry(fn, opts = {}) {
+  const retries = opts.retries ?? 1;
+  const min_delay = opts.minDelayMs ?? 500;
+  const jitter = opts.jitterMs ?? 500;
+  const classify = opts.isTransient ?? isTransient;
+  const sleep2 = opts.sleep ?? defaultSleep;
+  let attempt = 0;
+  for (; ; ) {
+    try {
+      return await fn();
+    } catch (err) {
+      if (attempt >= retries || !classify(err)) throw err;
+      attempt++;
+      await sleep2(min_delay + Math.floor(Math.random() * jitter));
+    }
+  }
+}
+function defaultSleep(ms) {
+  return new Promise((r) => setTimeout(r, ms));
+}
+
 // src/common.ts
 var VERSIONS_JSON = "https://ziglang.org/download/index.json";
 var MACH_VERSIONS_JSON = "https://pkg.machengine.org/zig/index.json";
@@ -68818,11 +68855,13 @@ function compareReleaseParts(a, b) {
   return a[0] - b[0] || a[1] - b[1] || a[2] - b[2];
 }
 async function fetchJsonWithTimeout(url2, timeout_ms) {
-  const resp = await fetch(url2, { signal: AbortSignal.timeout(timeout_ms) });
-  if (!resp.ok) {
-    throw new Error(`Fetch ${url2} failed: HTTP ${resp.status}`);
-  }
-  return await resp.json();
+  return await withRetry(async () => {
+    const resp = await fetch(url2, { signal: AbortSignal.timeout(timeout_ms) });
+    if (!resp.ok) {
+      throw new Error(`Fetch ${url2} failed: HTTP ${resp.status}`);
+    }
+    return await resp.json();
+  });
 }
 async function getTarballName() {
   const version3 = await getVersion2();
diff --git a/src/common.ts b/src/common.ts
index 1dbdfe7..9d92a96 100644
--- a/src/common.ts
+++ b/src/common.ts
@@ -10,6 +10,7 @@ import {
   lookupMachVersion,
 } from './schema.ts';
 import { errMessage, isErrnoException } from './util.ts';
+import { withRetry } from './retry.ts';
 
 const VERSIONS_JSON = 'https://ziglang.org/download/index.json';
 const MACH_VERSIONS_JSON = 'https://pkg.machengine.org/zig/index.json';
@@ -123,12 +124,17 @@ function compareReleaseParts(a: [number, number, number], b: [number, number, nu
   return (a[0] - b[0]) || (a[1] - b[1]) || (a[2] - b[2]);
 }
 
+// Version resolution happens before any mirror is contacted, so a single
+// slow response here fails the whole job with nothing else attempted. Retry
+// transient failures (timeout, 5xx, connection reset) once.
 async function fetchJsonWithTimeout(url: string, timeout_ms: number): Promise<unknown> {
-  const resp = await fetch(url, { signal: AbortSignal.timeout(timeout_ms) });
-  if (!resp.ok) {
-    throw new Error(`Fetch ${url} failed: HTTP ${resp.status}`);
-  }
-  return await resp.json();
+  return await withRetry(async () => {
+    const resp = await fetch(url, { signal: AbortSignal.timeout(timeout_ms) });
+    if (!resp.ok) {
+      throw new Error(`Fetch ${url} failed: HTTP ${resp.status}`);
+    }
+    return await resp.json();
+  });
 }
 
 export async function getTarballName(): Promise<string> {
diff --git a/src/retry.ts b/src/retry.ts
index c6a97d3..9da2e9f 100644
--- a/src/retry.ts
+++ b/src/retry.ts
@@ -11,7 +11,9 @@ export function isTransient(err: unknown): boolean {
   if (!(err instanceof Error)) return false;
   // AbortError sets err.name; the message ("The operation was aborted") does
   // not mention "abort" in a way we can grep reliably across runtimes.
-  if (err.name === 'AbortError') return true;
+  // AbortSignal.timeout() rejects with a DOMException named TimeoutError
+  // rather than AbortError — a slow mirror is transient, so retry it too.
+  if (err.name === 'AbortError' || err.name === 'TimeoutError') return true;
   const msg = err.message;
   // @actions/tool-cache and friends emit "Unexpected HTTP response: 5xx";
   // accept any non-digit run between "HTTP" and the status code.
diff --git a/test/retry.test.ts b/test/retry.test.ts
index 98488a2..6ea25b6 100644
--- a/test/retry.test.ts
+++ b/test/retry.test.ts
@@ -34,6 +34,18 @@ test('isTransient: common network errnos are transient', () => {
   assert.equal(isTransient(aborted), true);
 });
 
+test('isTransient: AbortSignal.timeout rejection is transient', async () => {
+  // The real shape a timed-out fetch produces: a DOMException named
+  // TimeoutError whose message mentions neither "abort" nor an errno.
+  const err = await new Promise<unknown>(resolve => {
+    AbortSignal.timeout(1).addEventListener('abort', function (this: AbortSignal) {
+      resolve(this.reason);
+    });
+  });
+  assert.equal((err as Error).name, 'TimeoutError');
+  assert.equal(isTransient(err), true);
+});
+
 test('isTransient: arbitrary application error is NOT transient', () => {
   assert.equal(isTransient(new Error('signature verification failed')), false);
   assert.equal(isTransient(new Error('filename mismatch')), false);