diff --git a/Library/Homebrew/formula.rb b/Library/Homebrew/formula.rb
index 2da151d6ef..15b9734fc9 100644
--- a/Library/Homebrew/formula.rb
+++ b/Library/Homebrew/formula.rb
@@ -638,7 +638,7 @@ class Formula
   # Explicitly request changing C++ standard library compatibility check
   # settings. Use with caution!
   def cxxstdlib_check check_type
-    @cxxstdlib << check_type
+    cxxstdlib << check_type
   end
 
   def self.method_added method