diff --git a/app/models/mute_rule.rb b/app/models/mute_rule.rb
index 14cfabf2..b5b828b4 100644
--- a/app/models/mute_rule.rb
+++ b/app/models/mute_rule.rb
@@ -2,6 +2,6 @@ class MuteRule < ApplicationRecord
   belongs_to :user
 
   def applies_to?(post)
-    !!(post.content =~ /\b#{muted_phrase}\b/i)
+    !!(post.content =~ /\b#{Regexp.escape(muted_phrase)}\b/i)
   end
 end