diff --git a/examples/with-firebase-authentication/next.config.js b/examples/with-firebase-authentication/next.config.js
new file mode 100644
index 0000000000000..ff566d92fe871
--- /dev/null
+++ b/examples/with-firebase-authentication/next.config.js
@@ -0,0 +1,9 @@
+// Parallel builds are currently broken due to a limitation in grpc (a transitive firebase
+// dependency). Until this is fixed, a workaround is to set the number of available CPUs to 1.
+// https://github.com/zeit/next.js/issues/7894
+// https://github.com/grpc/grpc-node/issues/778
+module.exports = {
+  experimental: {
+    cpus: 1
+  }
+}