diff --git a/middleman-core/lib/middleman-core/cli.rb b/middleman-core/lib/middleman-core/cli.rb
index f152530f..77f91624 100644
--- a/middleman-core/lib/middleman-core/cli.rb
+++ b/middleman-core/lib/middleman-core/cli.rb
@@ -71,7 +71,7 @@ module Middleman
         end
 
         if klass.nil?
-          super
+          raise Thor::Error.new "There's no '#{meth}' command for Middleman. Try 'middleman help' for a list of commands."
         else
           args.unshift(task) if task
           klass.start(args, :shell => self.shell)