diff --git a/packages/eslint-config-react-app/index.js b/packages/eslint-config-react-app/index.js
index 3dcce554046..386a34d6929 100644
--- a/packages/eslint-config-react-app/index.js
+++ b/packages/eslint-config-react-app/index.js
@@ -181,7 +181,7 @@ module.exports = {
     'no-unexpected-multiline': 'warn',
     'no-unreachable': 'warn',
     'no-unused-expressions': [
-      'warn',
+      'error',
       {
         allowShortCircuit: true,
         allowTernary: true,