diff --git a/.changeset/workers-builds-override-name.md b/.changeset/workers-builds-override-name.md
new file mode 100644
index 00000000..8d2eb56a
--- /dev/null
+++ b/.changeset/workers-builds-override-name.md
@@ -0,0 +1,5 @@
+---
+"@cloudhal/cli": patch
+---
+
+The Deploy to Cloudflare button deploys the admin Worker under its own name. Workers Builds sets `WRANGLER_CI_OVERRIDE_NAME` to the Worker a build is connected to, and wrangler then deploys every config under that name, so the admin Worker overwrote the site Worker (the site's address served Studio). `cloudhal deploy` no longer passes `WRANGLER_CI_OVERRIDE_NAME` or `WRANGLER_CI_MATCH_TAG` to wrangler; it names each Worker itself.
diff --git a/docs/guides/deploy-button.md b/docs/guides/deploy-button.md
index 6035d74b..c1dd8b65 100644
--- a/docs/guides/deploy-button.md
+++ b/docs/guides/deploy-button.md
@@ -43,3 +43,7 @@ Start from `npm create cloudhal@latest`, then:
 - commit `cloudhal.json` and a root `wrangler.jsonc` that names the site Worker, a `DB` D1 database (placeholder id `00000000-0000-0000-0000-000000000000`) and a `BLOBS` R2 bucket
 - remove the `build` script (Workers Builds would run it before `deploy`), keep `"deploy": "cloudhal deploy"`
 - commit a lockfile and a `.node-version` of `24`. The CLI runs on Node 24.
+
+## Before 0.3.2: the site Worker shows Studio
+
+Workers Builds sets `WRANGLER_CI_OVERRIDE_NAME` to the Worker a build is connected to. Before 0.3.2, `cloudhal deploy` passed it on to wrangler, so the admin Worker was uploaded under the site Worker's name. The site's address then served Studio, and no `<name>-admin` Worker existed. To fix a deployment made that way, bump `@cloudhal/*` in your copy of the template to 0.3.2 or later and push. The next build deploys both Workers under their own names.
diff --git a/packages/cli/src/cloudflare/wrangler.ts b/packages/cli/src/cloudflare/wrangler.ts
index 6e9983f7..a044dff2 100644
--- a/packages/cli/src/cloudflare/wrangler.ts
+++ b/packages/cli/src/cloudflare/wrangler.ts
@@ -70,7 +70,17 @@ export function wranglerRunner(
   return async (args, { cwd, quiet }) => {
     const dir = await mkdtemp(path.join(os.tmpdir(), "cloudhal-wrangler-"));
     const outputFile = path.join(dir, "output.ndjson");
-    const { VITEST: _v, NODE_ENV: _n, ...env } = process.env;
+    // Workers Builds sets WRANGLER_CI_OVERRIDE_NAME (and WRANGLER_CI_MATCH_TAG) to the one Worker
+    // the build is connected to; wrangler then deploys every config under that name. `cloudhal
+    // deploy` names each Worker itself (the site keeps the connected name), so the admin Worker
+    // would otherwise overwrite the site. Seen on the first Deploy to Cloudflare button run.
+    const {
+      VITEST: _v,
+      NODE_ENV: _n,
+      WRANGLER_CI_OVERRIDE_NAME: _ciName,
+      WRANGLER_CI_MATCH_TAG: _ciTag,
+      ...env
+    } = process.env;
     try {
       const result = await new Promise<{ code: number; stdout: string; stderr: string }>(
         (resolve) => {
diff --git a/packages/cli/test/wrangler-ci-env.test.ts b/packages/cli/test/wrangler-ci-env.test.ts
new file mode 100644
index 00000000..047ff409
--- /dev/null
+++ b/packages/cli/test/wrangler-ci-env.test.ts
@@ -0,0 +1,35 @@
+import { mkdir, mkdtemp, rm, writeFile } from "node:fs/promises";
+import os from "node:os";
+import path from "node:path";
+import { afterAll, describe, expect, it } from "vitest";
+import { wranglerRunner } from "../src/cloudflare/wrangler.ts";
+
+describe("wranglerRunner in Workers Builds", () => {
+  let dir: string;
+  afterAll(async () => {
+    if (dir) await rm(dir, { recursive: true, force: true });
+  });
+
+  it("does not pass the build's Worker-name override to wrangler", async () => {
+    dir = await mkdtemp(path.join(os.tmpdir(), "cloudhal-wrangler-env-"));
+    await writeFile(path.join(dir, "package.json"), "{}");
+    const pkg = path.join(dir, "node_modules/wrangler");
+    await mkdir(path.join(pkg, "bin"), { recursive: true });
+    await writeFile(path.join(pkg, "package.json"), '{"name":"wrangler","version":"4.151.0"}');
+    // A stand-in wrangler that prints the variables a real one would read.
+    await writeFile(
+      path.join(pkg, "bin/wrangler.js"),
+      "process.stdout.write(JSON.stringify({ name: process.env.WRANGLER_CI_OVERRIDE_NAME ?? null, tag: process.env.WRANGLER_CI_MATCH_TAG ?? null, ci: process.env.WORKERS_CI ?? null }));",
+    );
+    const saved = { ...process.env };
+    process.env.WRANGLER_CI_OVERRIDE_NAME = "my-blog-site";
+    process.env.WRANGLER_CI_MATCH_TAG = "tag123";
+    process.env.WORKERS_CI = "1";
+    try {
+      const r = await wranglerRunner(dir)(["deploy"], { cwd: dir, quiet: true });
+      expect(JSON.parse(r.stdout)).toEqual({ name: null, tag: null, ci: "1" });
+    } finally {
+      process.env = saved;
+    }
+  });
+});