diff --git a/Library/Homebrew/cask/audit.rb b/Library/Homebrew/cask/audit.rb
index 2367925e9e..097e2d8711 100644
--- a/Library/Homebrew/cask/audit.rb
+++ b/Library/Homebrew/cask/audit.rb
@@ -322,11 +322,11 @@ module Cask
 
     def check_https_availability
       return unless download
-      unless cask.url.to_s.empty? || cask.url.using
+      unless cask.url.blank? || cask.url.using
         check_url_for_https_availability(cask.url, user_agents: [cask.url.user_agent])
       end
-      check_url_for_https_availability(cask.appcast) unless cask.appcast.to_s.empty?
-      check_url_for_https_availability(cask.homepage) unless cask.homepage.to_s.empty?
+      check_url_for_https_availability(cask.appcast) unless cask.appcast.blank?
+      check_url_for_https_availability(cask.homepage) unless cask.homepage.blank?
     end
 
     def check_url_for_https_availability(url_to_check, user_agents: [:default])