diff --git a/Library/Homebrew/completions.rb b/Library/Homebrew/completions.rb
index 161f4cf5ea..43033ed4f8 100644
--- a/Library/Homebrew/completions.rb
+++ b/Library/Homebrew/completions.rb
@@ -223,7 +223,7 @@ module Homebrew
           next unless ZSH_NAMED_ARGS_COMPLETION_FUNCTION_MAPPING.key? type
 
           args_options << "- #{type}"
-          opt = "--#{type}"
+          opt = "--#{type.to_s.gsub(/(installed|outdated)_/, "")}"
           if options.key?(opt)
             desc = options[opt]