diff --git a/app/models/mute_rule.rb b/app/models/mute_rule.rb
index 6641c7ec..3e2a66af 100644
--- a/app/models/mute_rule.rb
+++ b/app/models/mute_rule.rb
@@ -1,7 +1,9 @@
+# frozen_string_literal: true
+
 class MuteRule < ApplicationRecord
   belongs_to :user
 
-  validates_presence_of :muted_phrase
+  validates :muted_phrase, presence: true
 
   def applies_to?(post)
     !!(post.content =~ /\b#{Regexp.escape(muted_phrase)}\b/i)