diff --git a/packages/app/e2e/browser/changes-pane.spec.ts b/packages/app/e2e/browser/changes-pane.spec.ts
index 637d1b633b..377adbb3b6 100644
--- a/packages/app/e2e/browser/changes-pane.spec.ts
+++ b/packages/app/e2e/browser/changes-pane.spec.ts
@@ -683,7 +683,7 @@ test("discarding a staged rename restores its source path", async ({ page }) =>
 
   const panel = page.getByTestId("working-diff-panel").filter({ visible: true });
   const renamedHeader = diffHeaderForPath(panel, "src/zz-renamed.ts");
-  await expect(renamedHeader).toHaveAccessibleName("src/zz-renamed.ts, +1, -0");
+  await expect(renamedHeader).toHaveAccessibleName("src/zz-renamed.ts, +0, -0");
   const renamedToggle = renamedHeader.getByTestId(/^diff-file-\d+-toggle$/);
   const toggleTestId = await renamedToggle.getAttribute("data-testid");
   expect(toggleTestId).not.toBeNull();
diff --git a/packages/app/vitest-environment.test.ts b/packages/app/vitest-environment.test.ts
new file mode 100644
index 0000000000..8d66f37e7f
--- /dev/null
+++ b/packages/app/vitest-environment.test.ts
@@ -0,0 +1,37 @@
+import { spawnSync } from "node:child_process";
+import { createRequire } from "node:module";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+import { expect, it } from "vitest";
+
+const appDir = fileURLToPath(new URL(".", import.meta.url));
+const rootDir = path.resolve(appDir, "../..");
+const require = createRequire(import.meta.url);
+const vitestEntry = path.join(path.dirname(require.resolve("vitest/package.json")), "vitest.mjs");
+
+it.each([
+  {
+    name: "root",
+    cwd: rootDir,
+    args: ["packages/app/src/screens/workspace/use-mounted-tab-set.test.ts"],
+  },
+  {
+    name: "app",
+    cwd: appDir,
+    args: ["--project", "unit", "src/screens/workspace/use-mounted-tab-set.test.ts"],
+  },
+])(
+  "$name tests can render React when the shell exports NODE_ENV=production",
+  ({ cwd, args }) => {
+    const result = spawnSync(process.execPath, [vitestEntry, "run", ...args], {
+      cwd,
+      env: { ...process.env, NODE_ENV: "production" },
+      encoding: "utf8",
+      timeout: 30_000,
+    });
+
+    expect(result.error).toBeUndefined();
+    expect(result.status, result.stdout + result.stderr).toBe(0);
+  },
+  40_000,
+);
diff --git a/packages/app/vitest.config.ts b/packages/app/vitest.config.ts
index 3838948be9..7fb338b040 100644
--- a/packages/app/vitest.config.ts
+++ b/packages/app/vitest.config.ts
@@ -3,6 +3,9 @@ import { playwright } from "@vitest/browser-playwright";
 import path from "path";
 import fs from "fs";
 
+// Set this before Vite resolves dependencies and Vitest starts its workers.
+process.env.NODE_ENV = "test";
+
 const appNodeModules = path.resolve(__dirname, "node_modules");
 const rootNodeModules = path.resolve(__dirname, "../../node_modules");
 const resolvePackageEntry = (packageName: string) => {
@@ -26,6 +29,7 @@ export default defineConfig({
             "src/**/*.{test,spec}.{ts,tsx}",
             "native-release-version.test.ts",
             "app.config.test.ts",
+            "vitest-environment.test.ts",
           ],
           setupFiles: [path.resolve(__dirname, "vitest.setup.ts")],
           exclude: [...configDefaults.exclude, "e2e/**", "src/**/*.browser.{test,spec}.{ts,tsx}"],
diff --git a/vitest.config.ts b/vitest.config.ts
index 77e75f6d6c..47bd965113 100644
--- a/vitest.config.ts
+++ b/vitest.config.ts
@@ -2,6 +2,9 @@ import fs from "node:fs";
 import path from "node:path";
 import { configDefaults, defineConfig } from "vitest/config";
 
+// React's test APIs require its development build, even in a production shell.
+process.env.NODE_ENV = "test";
+
 const appDir = path.resolve(__dirname, "packages/app");
 const appNodeModules = path.resolve(appDir, "node_modules");
 const rootNodeModules = path.resolve(__dirname, "node_modules");