diff --git a/Library/Homebrew/cask/lib/hbc/cli.rb b/Library/Homebrew/cask/lib/hbc/cli.rb
index bd50e41a62..437b0d72c6 100644
--- a/Library/Homebrew/cask/lib/hbc/cli.rb
+++ b/Library/Homebrew/cask/lib/hbc/cli.rb
@@ -230,7 +230,6 @@ module Hbc
 
         return if @command == "help" && @args.empty?
 
-        unknown_command = @args.empty? ? @command : @args.first
         raise ArgumentError, "Unknown command: #{@command} #{@args.join(" ")}"
       end