diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index f9274313a..5a7c2d813 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -78,9 +78,15 @@ jobs:
       - name: Build packages
         run: pnpm exec turbo build --filter='...[origin/${{ github.base_ref }}]' --filter='!gt-next-middleware-e2e' --filter='!./examples/*'
 
+      - name: Run typecheck
+        run: pnpm exec turbo typecheck --filter='...[origin/${{ github.base_ref }}]' --filter='!gt-next-middleware-e2e' --filter='!./examples/*'
+
       - name: Run tests
         run: pnpm exec turbo test --filter='...[origin/${{ github.base_ref }}]' --filter='!gt-next-middleware-e2e' --filter='!./examples/*'
 
+      - name: Run smoke tests
+        run: pnpm exec turbo smoke --filter='...[origin/${{ github.base_ref }}]' --filter='!gt-next-middleware-e2e' --filter='!./examples/*'
+
   test-builds:
     strategy:
       matrix:
diff --git a/packages/next/package.json b/packages/next/package.json
index c63f7be5f..c3c4aaf53 100644
--- a/packages/next/package.json
+++ b/packages/next/package.json
@@ -49,7 +49,8 @@
     "test:watch": "vitest",
     "bench": "vitest bench --run --config vitest.config.bench.ts",
     "bench:unit:json": "vitest bench --run --config vitest.config.bench.ts --outputJson benchmarks/results/unit-latest.json",
-    "typecheck": "tsc --noEmit"
+    "typecheck": "tsc --noEmit",
+    "smoke": "node scripts/smoke.mjs"
   },
   "repository": {
     "type": "git",
diff --git a/packages/next/scripts/smoke.mjs b/packages/next/scripts/smoke.mjs
new file mode 100644
index 000000000..e1fed47c0
--- /dev/null
+++ b/packages/next/scripts/smoke.mjs
@@ -0,0 +1,37 @@
+#!/usr/bin/env node
+// Import the built `gt-next/config` entry the way a real next.config does:
+// plain Node, no bundler. Catches module-evaluation-time regressions the
+// bundled test apps can't (e.g. bare `require`/`__dirname` in the ESM build,
+// exports-map paths pointing at files that don't exist).
+import { createRequire } from 'node:module';
+
+const failures = [];
+
+try {
+  const esm = await import('gt-next/config');
+  if (typeof esm.withGTConfig !== 'function') {
+    failures.push('ESM: withGTConfig is not a function');
+  }
+} catch (error) {
+  failures.push(`ESM: import('gt-next/config') threw: ${error}`);
+}
+
+try {
+  const require = createRequire(import.meta.url);
+  const cjs = require('gt-next/config');
+  if (typeof cjs.withGTConfig !== 'function') {
+    failures.push('CJS: withGTConfig is not a function');
+  }
+} catch (error) {
+  failures.push(`CJS: require('gt-next/config') threw: ${error}`);
+}
+
+if (failures.length > 0) {
+  console.error('gt-next smoke test failed:');
+  for (const failure of failures) {
+    console.error(`  - ${failure}`);
+  }
+  process.exit(1);
+}
+
+console.warn('gt-next smoke test passed (ESM + CJS config entry)');
diff --git a/turbo.json b/turbo.json
index 9eded66da..8b0996434 100644
--- a/turbo.json
+++ b/turbo.json
@@ -27,6 +27,10 @@
       "cache": false,
       "env": ["VITE_CI_TEST_GT_PROJECT_ID", "VITE_CI_TEST_GT_API_KEY"]
     },
+    "smoke": {
+      "dependsOn": ["build", "^build"],
+      "cache": false
+    },
     "test:watch": {
       "cache": false,
       "persistent": true