diff --git a/.github/workflows/kilo-app-ci.yml b/.github/workflows/kilo-app-ci.yml
index 1c0a951080..1bfed09671 100644
--- a/.github/workflows/kilo-app-ci.yml
+++ b/.github/workflows/kilo-app-ci.yml
@@ -65,6 +65,11 @@ jobs:
       - name: Typecheck
         run: pnpm --filter kilo-app run typecheck
 
+      # The release preflight is the only other job that evaluates app.config.ts,
+      # and it runs nightly. Read the config here so a broken import fails the PR.
+      - name: Read Expo config
+        run: pnpm --filter kilo-app exec expo config --type public > /dev/null
+
   lint:
     runs-on: ${{ vars.RUNNER_DEFAULT_LABEL || 'ubuntu-latest' }}
     timeout-minutes: 15
diff --git a/apps/mobile/app.config.ts b/apps/mobile/app.config.ts
index 22988dad73..fcf03d8964 100644
--- a/apps/mobile/app.config.ts
+++ b/apps/mobile/app.config.ts
@@ -1,6 +1,6 @@
 import type { ExpoConfig } from 'expo/config';
 import { ENV_KEYS, OPTIONAL_ENV_KEYS } from './src/lib/env-keys';
-import { SUPPORTED_LANGUAGES } from './src/i18n/languages';
+import { SUPPORTED_LANGUAGES } from './src/i18n/languages.ts';
 import { SENTRY_NATIVE_OPTIONS } from './src/lib/sentry-dsn';
 import { UNIVERSAL_LINK_PATH_PATTERNS } from './src/lib/universal-link-paths';
 import {
diff --git a/apps/mobile/tsconfig.json b/apps/mobile/tsconfig.json
index 87c03988c8..57579343b5 100644
--- a/apps/mobile/tsconfig.json
+++ b/apps/mobile/tsconfig.json
@@ -2,6 +2,9 @@
   "extends": "expo/tsconfig.base",
   "compilerOptions": {
     "strict": true,
+    // app.config.ts imports src/i18n/languages.ts with its extension: the Expo
+    // config loader resolves require('./x.ts') but not the extensionless form.
+    "allowImportingTsExtensions": true,
     "noUncheckedIndexedAccess": true,
     "paths": {
       "@/*": ["./src/*"],