diff --git a/src/lint/linter/ArcanistESLintLinter.php b/src/lint/linter/ArcanistESLintLinter.php
--- a/src/lint/linter/ArcanistESLintLinter.php
+++ b/src/lint/linter/ArcanistESLintLinter.php
@@ -40,7 +40,7 @@
         return pht('Install ESLint using `%s`.', 'npm install -g eslint');
     }
 
-    public function getMandatoryFlags() {
+    protected function getMandatoryFlags() {
         $options = array();
 
         $options[] = '--format=stylish';