diff --git a/Library/Homebrew/cask/lib/hbc/cli/doctor.rb b/Library/Homebrew/cask/lib/hbc/cli/doctor.rb
index 32b927218b6b893dcc250bf3b2626041f05e0005..6f00951724d8808a0792ec68411138a1b883fe4f 100644
--- a/Library/Homebrew/cask/lib/hbc/cli/doctor.rb
+++ b/Library/Homebrew/cask/lib/hbc/cli/doctor.rb
@@ -124,6 +124,7 @@ module Hbc
           BUNDLE_PATH
           PATH
           SHELL
+          HOMEBREW_CASK_OPTS
         ]
 
         locale_variables = ENV.keys.grep(/^(?:LC_\S+|LANG|LANGUAGE)\Z/).sort