diff --git a/Library/Homebrew/cask/lib/hbc/cli.rb b/Library/Homebrew/cask/lib/hbc/cli.rb
index 7f59954b58..92f0333ad8 100644
--- a/Library/Homebrew/cask/lib/hbc/cli.rb
+++ b/Library/Homebrew/cask/lib/hbc/cli.rb
@@ -154,7 +154,7 @@ module Hbc
     def run
       command_name, *args = detect_command_and_arguments(*@args)
       command = if help?
-        args.unshift(command_name) unless command_name.nil
+        args.unshift(command_name) unless command_name.nil?
         "help"
       else
         self.class.lookup_command(command_name)