diff --git a/packages/eslint-config-react-app/index.js b/packages/eslint-config-react-app/index.js
index f029f9626bfccbf83b9c2551a491224479806857..6bb7897ff63795fa94b0aff63d92f1c034ee58bf 100644
--- a/packages/eslint-config-react-app/index.js
+++ b/packages/eslint-config-react-app/index.js
@@ -120,7 +120,7 @@ module.exports = {
     'no-unexpected-multiline': 'warn',
     'no-unreachable': 'warn',
     'no-unused-expressions': [
-      'warn',
+      'error',
       {
         allowShortCircuit: true,
         allowTernary: true,