diff --git a/arcanist/linter/CppCheckLinter.php b/arcanist/linter/CppCheckLinter.php
--- a/arcanist/linter/CppCheckLinter.php
+++ b/arcanist/linter/CppCheckLinter.php
@@ -169,7 +169,7 @@
   protected function getDefaultFlags() {
     return array_merge(
       self::CPPCHECK_OPTIONS,
-      self::CPPCHECK_DEFINITIONS,
+      self::CPPCHECK_DEFINITIONS
     );
   }