diff --git a/de_shell/js/main/pythonEnv.test.ts b/de_shell/js/main/pythonEnv.test.ts
index a531f28..3c71f7a 100644
--- a/de_shell/js/main/pythonEnv.test.ts
+++ b/de_shell/js/main/pythonEnv.test.ts
@@ -25,10 +25,12 @@ import { dirname, join } from 'path'
 import { tmpdir } from 'os'
 import { createHash } from 'crypto'
 import { configureShell } from './config.ts'
+import { parseUvLine } from './envProgress.ts'
 import {
   findUv, resolvePythonEnv, hasNvidiaGpu, readWheelhouse, findWheelhouse,
   wheelhouseCandidates, lockStamp, buildSyncArgs, offlinePlan, effectiveExtras,
   gpuEnvOverride, platformMatches, fileUrl, checkWheelhouseExtras, venvPython, clearBrokenEnv,
+  withoutPythonDownloadLines,
 } from './pythonEnv.ts'
 
 configureShell({
@@ -284,6 +286,44 @@ test('offlinePlan builds the python, venv, export, pip-install sequence', () =>
   assert.equal(plan.install.at(-1), venvPython(join('/ud', 'python-env')))
 })
 
+/** uv 0.13.4's output for the wheelhouse's interpreter step, piped (de-shell #31). */
+const UV_PYTHON_FROM_MIRROR =
+  'Downloading cpython-3.13.12-windows-x86_64-none (download) (20.7MiB)\n' +
+  ' Downloaded cpython-3.13.12-windows-x86_64-none (download)\n' +
+  'Installed Python 3.13.12 in 1.22s\n' +
+  ' + cpython-3.13.12-windows-x86_64-none\n'
+
+function relayed(chunks: string[]): string {
+  const out: string[] = []
+  const python = withoutPythonDownloadLines((s) => out.push(s))
+  for (const chunk of chunks) python.relay(chunk)
+  python.flush()
+  return out.join('')
+}
+
+test('the wheelhouse interpreter step drops uv\'s download lines and keeps the rest', () => {
+  assert.equal(relayed([UV_PYTHON_FROM_MIRROR]),
+    'Installed Python 3.13.12 in 1.22s\n + cpython-3.13.12-windows-x86_64-none\n')
+})
+
+test('a download line split across chunks is still dropped whole', () => {
+  const cut = UV_PYTHON_FROM_MIRROR.indexOf('(download) (20.7MiB)')
+  assert.equal(relayed([UV_PYTHON_FROM_MIRROR.slice(0, cut), UV_PYTHON_FROM_MIRROR.slice(cut)]),
+    'Installed Python 3.13.12 in 1.22s\n + cpython-3.13.12-windows-x86_64-none\n')
+})
+
+test('an unfinished last line reaches the progress stream at flush', () => {
+  assert.equal(relayed(['error: no Python in the mirror']), 'error: no Python in the mirror')
+})
+
+test('the setup window reads the offline interpreter step as an install, never a download', () => {
+  const lines = ('[env-setup] installing Python 3.13.12 from the wheelhouse\n' +
+    relayed([UV_PYTHON_FROM_MIRROR])).split('\n')
+  const events = lines.map(parseUvLine).filter((e) => e !== null)
+  assert.equal(events[0]?.step, 'Installing Python 3.13.12 from the wheelhouse')
+  assert.deepEqual(events.filter((e) => e.phase === 'downloading'), [])
+})
+
 test('checkWheelhouseExtras names the missing extra', () => {
   const m = { ...goodManifest, extras: [] }
   assert.throws(() => checkWheelhouseExtras(['gpu'], m), /built without the 'gpu' extra/)
diff --git a/de_shell/js/main/pythonEnv.ts b/de_shell/js/main/pythonEnv.ts
index 6d0ad93..cf455d5 100644
--- a/de_shell/js/main/pythonEnv.ts
+++ b/de_shell/js/main/pythonEnv.ts
@@ -625,6 +625,39 @@ function runUv(
   })
 }
 
+/** uv's words for copying an interpreter from its install mirror. */
+const PYTHON_DOWNLOAD_LINE = /^ *Download(?:ing|ed) cpython-/
+
+/**
+ * A progress relay for the wheelhouse's interpreter step. Its mirror is the
+ * wheelhouse's `python/` folder on disk, but uv words the copy as a download
+ * ("Downloading cpython-…", "Downloaded cpython-…"), and the setup window would
+ * show it as one. Those lines are dropped and the rest passed on. Whole lines
+ * only: a chunk's unfinished last line is held until its end arrives, or `flush`.
+ */
+export function withoutPythonDownloadLines(onProgress?: (line: string) => void): {
+  relay: (chunk: string) => void
+  flush: () => void
+} {
+  let held = ''
+  const pass = (text: string) => {
+    const kept = text.split(/(?<=\n)/).filter((line) => !PYTHON_DOWNLOAD_LINE.test(line)).join('')
+    if (kept) onProgress?.(kept)
+  }
+  return {
+    relay(chunk) {
+      const text = held + chunk
+      const end = text.lastIndexOf('\n') + 1
+      held = text.slice(end)
+      if (end) pass(text.slice(0, end))
+    },
+    flush() {
+      if (held) pass(held)
+      held = ''
+    },
+  }
+}
+
 /**
  * Install the locked torch release into the managed env with the backend
  * resolved for THIS machine (`--torch-backend=auto`: uv probes the NVIDIA
@@ -772,7 +805,14 @@ async function setupEnv(o: {
     onProgress?.(`[env-setup] offline install from wheelhouse ${dir}\n`)
     const plan = offlinePlan({ wheelhouse: dir, manifest, envDir, userData: join(envDir, '..'), extras })
     mkdirSync(join(envDir, '..'), { recursive: true })
-    await runUv(projectDir, envDir, plan.python, appVersion, onProgress, plan.env)
+    onProgress?.(`[env-setup] installing Python ${manifest.python} from the wheelhouse
+`)
+    const python = withoutPythonDownloadLines(onProgress)
+    try {
+      await runUv(projectDir, envDir, plan.python, appVersion, python.relay, plan.env)
+    } finally {
+      python.flush()
+    }
     await runUv(projectDir, envDir, plan.venv, appVersion, onProgress, plan.env)
     await runUv(projectDir, envDir, plan.export, appVersion, onProgress, plan.env)
     await runUv(projectDir, envDir, plan.install, appVersion, onProgress, plan.env)
diff --git a/upcoming_changes/32.bugfix.rst b/upcoming_changes/32.bugfix.rst
new file mode 100644
index 0000000..c5b7b92
--- /dev/null
+++ b/upcoming_changes/32.bugfix.rst
@@ -0,0 +1 @@
+An offline install's setup window said it was downloading Python, although the interpreter is copied from the wheelhouse; it now says it is installing Python from the wheelhouse.