diff --git a/Library/Homebrew/deprecate_disable.rb b/Library/Homebrew/deprecate_disable.rb
index 8140139458..fcd8081954 100644
--- a/Library/Homebrew/deprecate_disable.rb
+++ b/Library/Homebrew/deprecate_disable.rb
@@ -28,6 +28,7 @@ module DeprecateDisable
     no_longer_available:      "is no longer available upstream",
     no_longer_meets_criteria: "no longer meets the criteria for acceptable casks",
     unmaintained:             "is not maintained upstream",
+    unsigned:                 "is unsigned or does not meet signature requirements",
   }.freeze
 
   def type(formula_or_cask)