diff --git a/packages/cli/config/eslint.backend.js b/packages/cli/config/eslint.backend.js
index 7acb538d38..6739d1c2ce 100644
--- a/packages/cli/config/eslint.backend.js
+++ b/packages/cli/config/eslint.backend.js
@@ -38,8 +38,8 @@ module.exports = {
   },
   ignorePatterns: ['.eslintrc.js', '**/dist/**', '**/dist-types/**'],
   rules: {
-    '@typescript-eslint/no-shadow': 'off',
-    '@typescript-eslint/no-redeclare': 'off',
+    '@typescript-eslint/no-shadow': 'error',
+    '@typescript-eslint/no-redeclare': 'error',
 
     'no-console': 0, // Permitted in console programs
     'new-cap': ['error', { capIsNew: false }], // Because Express constructs things e.g. like 'const r = express.Router()'
diff --git a/packages/cli/config/eslint.js b/packages/cli/config/eslint.js
index 044d737d15..c440e53bc0 100644
--- a/packages/cli/config/eslint.js
+++ b/packages/cli/config/eslint.js
@@ -45,9 +45,9 @@ module.exports = {
   },
   ignorePatterns: ['.eslintrc.js', '**/dist/**', '**/dist-types/**'],
   rules: {
-    '@typescript-eslint/no-shadow': 'off',
-    '@typescript-eslint/no-redeclare': 'off',
-    'no-undef': 'off',
+    '@typescript-eslint/no-shadow': 'error',
+    '@typescript-eslint/no-redeclare': 'error',
+
     'import/newline-after-import': 'error',
     'import/no-duplicates': 'warn',
     'import/no-extraneous-dependencies': [