diff --git a/Library/Homebrew/rubocops/cask/url_legacy_comma_separators.rb b/Library/Homebrew/rubocops/cask/url_legacy_comma_separators.rb
index 7dadc4bd07..d164e625a2 100644
--- a/Library/Homebrew/rubocops/cask/url_legacy_comma_separators.rb
+++ b/Library/Homebrew/rubocops/cask/url_legacy_comma_separators.rb
@@ -20,7 +20,7 @@ module RuboCop
 
           url_node = stanza.stanza_node.first_argument
 
-          legacy_comma_separator_pattern = /version.(before|after)_comma/
+          legacy_comma_separator_pattern = /version\.(before|after)_comma/
 
           url = url_node.source