diff --git a/Library/Homebrew/cmd/completions.rb b/Library/Homebrew/cmd/completions.rb
index ac7a8e2a5f..2fd15596ce 100644
--- a/Library/Homebrew/cmd/completions.rb
+++ b/Library/Homebrew/cmd/completions.rb
@@ -1,49 +1,46 @@
 # typed: strict
 # frozen_string_literal: true
 
-require "cli/parser"
+require "abstract_command"
 require "completions"
 
 module Homebrew
-  module_function
+  module Cmd
+    class CompletionsCmd < AbstractCommand
+      cmd_args do
+        description <<~EOS
+          Control whether Homebrew automatically links external tap shell completion files.
+          Read more at <https://docs.brew.sh/Shell-Completion>.
 
-  sig { returns(CLI::Parser) }
-  def completions_args
-    Homebrew::CLI::Parser.new do
-      description <<~EOS
-        Control whether Homebrew automatically links external tap shell completion files.
-        Read more at <https://docs.brew.sh/Shell-Completion>.
+          `brew completions` [`state`]:
+          Display the current state of Homebrew's completions.
 
-        `brew completions` [`state`]:
-        Display the current state of Homebrew's completions.
+          `brew completions` (`link`|`unlink`):
+          Link or unlink Homebrew's completions.
+        EOS
 
-        `brew completions` (`link`|`unlink`):
-        Link or unlink Homebrew's completions.
-      EOS
-
-      named_args %w[state link unlink], max: 1
-    end
-  end
-
-  sig { void }
-  def completions
-    args = completions_args.parse
-
-    case args.named.first
-    when nil, "state"
-      if Completions.link_completions?
-        puts "Completions are linked."
-      else
-        puts "Completions are not linked."
+        named_args %w[state link unlink], max: 1
+      end
+
+      sig { override.void }
+      def run
+        case args.named.first
+        when nil, "state"
+          if Completions.link_completions?
+            puts "Completions are linked."
+          else
+            puts "Completions are not linked."
+          end
+        when "link"
+          Completions.link!
+          puts "Completions are now linked."
+        when "unlink"
+          Completions.unlink!
+          puts "Completions are no longer linked."
+        else
+          raise UsageError, "unknown subcommand: #{args.named.first}"
+        end
       end
-    when "link"
-      Completions.link!
-      puts "Completions are now linked."
-    when "unlink"
-      Completions.unlink!
-      puts "Completions are no longer linked."
-    else
-      raise UsageError, "unknown subcommand: #{args.named.first}"
     end
   end
 end
diff --git a/Library/Homebrew/test/cmd/completions_spec.rb b/Library/Homebrew/test/cmd/completions_spec.rb
index ab0bd90a63..6cc7cc2496 100644
--- a/Library/Homebrew/test/cmd/completions_spec.rb
+++ b/Library/Homebrew/test/cmd/completions_spec.rb
@@ -1,8 +1,9 @@
 # frozen_string_literal: true
 
+require "cmd/completions"
 require "cmd/shared_examples/args_parse"
 
-RSpec.describe "brew completions" do
+RSpec.describe Homebrew::Cmd::CompletionsCmd do
   it_behaves_like "parseable arguments"
 
   it "runs the status subcommand correctly", :integration_test do