diff --git a/electron/audio/capture-preload-utils.cjs b/electron/audio/capture-preload-utils.cjs
new file mode 100644
index 0000000..6c972fb
--- /dev/null
+++ b/electron/audio/capture-preload-utils.cjs
@@ -0,0 +1,24 @@
+function serializeError(error) {
+  return {
+    message: error instanceof Error ? error.message : String(error),
+    name: error && typeof error.name === "string" ? error.name : "",
+  };
+}
+
+function handleRecorderStop({ sendChain, id, getStopEpoch, cleanup, send }) {
+  return sendChain
+    .then(() => {
+      const stopEpoch = getStopEpoch();
+      cleanup();
+      send("audio:stopped", id, stopEpoch);
+    })
+    .catch((error) => {
+      const stopEpoch = getStopEpoch();
+      cleanup();
+      const detail = serializeError(error);
+      send("audio:error", id, detail.message, detail.name);
+      send("audio:stopped", id, stopEpoch);
+    });
+}
+
+module.exports = { handleRecorderStop, serializeError };
diff --git a/electron/audio/capture-preload-utils.test.ts b/electron/audio/capture-preload-utils.test.ts
new file mode 100644
index 0000000..0e443c2
--- /dev/null
+++ b/electron/audio/capture-preload-utils.test.ts
@@ -0,0 +1,45 @@
+import assert from "node:assert/strict";
+import { createRequire } from "node:module";
+import test from "node:test";
+
+const require = createRequire(import.meta.url);
+const { handleRecorderStop } = require("./capture-preload-utils.cjs");
+
+test("audio stop reports a rejected chunk flush", async () => {
+  const events: unknown[][] = [];
+  let cleaned = false;
+  await handleRecorderStop({
+    sendChain: Promise.reject(new Error("chunk flush failed")),
+    id: "segment-0001",
+    getStopEpoch: () => 123,
+    cleanup: () => {
+      cleaned = true;
+    },
+    send: (...args: unknown[]) => {
+      events.push(args);
+    },
+  });
+  assert.equal(cleaned, true);
+  assert.deepEqual(events, [
+    ["audio:error", "segment-0001", "chunk flush failed", "Error"],
+    ["audio:stopped", "segment-0001", 123],
+  ]);
+});
+
+test("audio stop acknowledges a successful chunk flush", async () => {
+  const events: unknown[][] = [];
+  let cleaned = false;
+  await handleRecorderStop({
+    sendChain: Promise.resolve(),
+    id: "segment-0001",
+    getStopEpoch: () => 123,
+    cleanup: () => {
+      cleaned = true;
+    },
+    send: (...args: unknown[]) => {
+      events.push(args);
+    },
+  });
+  assert.equal(cleaned, true);
+  assert.deepEqual(events, [["audio:stopped", "segment-0001", 123]]);
+});
diff --git a/electron/audio/capture-preload.cjs b/electron/audio/capture-preload.cjs
index 2c32d24..3f6d786 100644
--- a/electron/audio/capture-preload.cjs
+++ b/electron/audio/capture-preload.cjs
@@ -5,6 +5,7 @@
 // mirror electron/audio/recorder.ts.
 const { ipcRenderer } = require("electron");
 const { readFile } = require("node:fs/promises");
+const { handleRecorderStop, serializeError } = require("./capture-preload-utils.cjs");
 
 /** @type {MediaRecorder | null} */
 let recorder = null;
@@ -29,13 +30,6 @@ function microphoneConstraints(deviceId) {
   };
 }
 
-function serializeError(error) {
-  return {
-    message: error instanceof Error ? error.message : String(error),
-    name: error && typeof error.name === "string" ? error.name : "",
-  };
-}
-
 async function enumerateMicrophones() {
   if (!navigator.mediaDevices || !navigator.mediaDevices.enumerateDevices) return [];
   const devices = await navigator.mediaDevices.enumerateDevices();
@@ -136,10 +130,12 @@ ipcRenderer.on("audio:start", async (_event, opts) => {
     };
     recorder.onstop = () => {
       // Wait for every queued chunk (including the final one) to be sent.
-      sendChain.then(() => {
-        const stopEpoch = requestedStopEpoch || epochNow();
-        cleanup();
-        ipcRenderer.send("audio:stopped", id, stopEpoch);
+      void handleRecorderStop({
+        sendChain,
+        id,
+        getStopEpoch: () => requestedStopEpoch || epochNow(),
+        cleanup,
+        send: (...args) => ipcRenderer.send(...args),
       });
     };
     recorder.onerror = (e) => {
diff --git a/package.json b/package.json
index dd1ac9a..2014835 100644
--- a/package.json
+++ b/package.json
@@ -19,7 +19,7 @@
     "check:lockfile": "node scripts/check-lockfile-portability.mjs",
     "typecheck": "tsc --noEmit",
     "typecheck:evals": "tsc --noEmit -p evals/tsconfig.json",
-    "test": "node --experimental-transform-types --no-warnings --import ./evals/register.mjs --test evals/builder-imports.test.ts common/architecture-registry.test.ts electron/architectures/catalogue-registry.test.ts common/audio.test.ts common/microphone.test.ts common/screen.test.ts common/narration.test.ts common/sensitive.test.ts common/skill.test.ts electron/recording-controls-bounds.test.ts electron/recorder-window-sizing.test.ts electron/recording-privacy.test.ts electron/crash-guards.test.ts electron/copilot-signin-auth.test.ts electron/copilot-signin-flow.test.ts electron/copilot-signin-process.test.ts electron/microsoft-signin-hint.test.ts src/analysis-recovery.test.ts electron/recorder/controller.test.ts electron/recorder/session-store.test.ts electron/frames/extractor.test.ts electron/pipeline.test.ts electron/narration/audio-analysis.test.ts electron/narration/analyze-gate.test.ts electron/narration/transcribe.test.ts electron/narration/whisper.test.ts electron/sensitive/scanner.test.ts electron/sensitive/secrets.test.ts electron/sensitive/tessdata-source.test.ts electron/sensitive/ocr.test.ts electron/sensitive/frame-redact.test.ts electron/sensitive/frame-heuristics.test.ts electron/terminal/terminal.test.ts electron/sessions.test.ts electron/debug-bundle.test.ts electron/skillbuilder/plan-tools.test.ts electron/skillbuilder/placement.test.ts electron/skillbuilder/preview.test.ts src/skill-placement.test.ts src/skill-review-state.test.ts scripts/compliance.test.mjs scripts/install-windows-dependencies.test.mjs",
+    "test": "node --experimental-transform-types --no-warnings --import ./evals/register.mjs --test evals/builder-imports.test.ts common/architecture-registry.test.ts electron/architectures/catalogue-registry.test.ts electron/audio/capture-preload-utils.test.ts common/audio.test.ts common/microphone.test.ts common/screen.test.ts common/narration.test.ts common/sensitive.test.ts common/skill.test.ts electron/recording-controls-bounds.test.ts electron/recorder-window-sizing.test.ts electron/recording-privacy.test.ts electron/crash-guards.test.ts electron/copilot-signin-auth.test.ts electron/copilot-signin-flow.test.ts electron/copilot-signin-process.test.ts electron/microsoft-signin-hint.test.ts src/analysis-recovery.test.ts electron/recorder/controller.test.ts electron/recorder/session-store.test.ts electron/frames/extractor.test.ts electron/pipeline.test.ts electron/narration/audio-analysis.test.ts electron/narration/analyze-gate.test.ts electron/narration/transcribe.test.ts electron/narration/whisper.test.ts electron/sensitive/scanner.test.ts electron/sensitive/secrets.test.ts electron/sensitive/tessdata-source.test.ts electron/sensitive/ocr.test.ts electron/sensitive/frame-redact.test.ts electron/sensitive/frame-heuristics.test.ts electron/terminal/terminal.test.ts electron/sessions.test.ts electron/debug-bundle.test.ts electron/skillbuilder/plan-tools.test.ts electron/skillbuilder/placement.test.ts electron/skillbuilder/preview.test.ts src/skill-placement.test.ts src/skill-review-state.test.ts scripts/compliance.test.mjs scripts/install-windows-dependencies.test.mjs",
     "eval": "node --experimental-transform-types --no-warnings --import ./evals/register.mjs evals/run.ts",
     "eval:terminal": "node --experimental-transform-types --no-warnings --import ./evals/register.mjs evals/run.ts --only=terminal-output-required,terminal-failure-recovery,terminal-sensitive-output",
     "eval:builder": "node --experimental-transform-types --no-warnings --import ./evals/register.mjs evals/builder/run.ts",
diff --git a/vite.config.ts b/vite.config.ts
index cefdf0a..bf0ade8 100644
--- a/vite.config.ts
+++ b/vite.config.ts
@@ -38,6 +38,10 @@ function copyStaticAssets(): void {
     path.join(rootDir, "electron", "audio", "capture-preload.cjs"),
     path.join(out, "audio", "capture-preload.cjs"),
   );
+  copyFileSync(
+    path.join(rootDir, "electron", "audio", "capture-preload-utils.cjs"),
+    path.join(out, "audio", "capture-preload-utils.cjs"),
+  );
 }
 
 export default defineConfig({