diff --git a/Library/Homebrew/cask/cask.rb b/Library/Homebrew/cask/cask.rb
index a98609d7b8..fc76d85389 100644
--- a/Library/Homebrew/cask/cask.rb
+++ b/Library/Homebrew/cask/cask.rb
@@ -87,7 +87,7 @@ module Cask
     def old_tokens
       @old_tokens ||= if (tap = self.tap)
         Tap.reverse_tap_migrations_renames.fetch("#{tap}/#{token}", []) +
-          tap.reverse_cask_renames.fetch(token, [])
+          tap.cask_reverse_renames.fetch(token, [])
       else
         []
       end
diff --git a/Library/Homebrew/tap.rb b/Library/Homebrew/tap.rb
index dce6e3e135..09538cfb1c 100644
--- a/Library/Homebrew/tap.rb
+++ b/Library/Homebrew/tap.rb
@@ -164,6 +164,7 @@ class Tap
     @formula_reverse_renames = nil
     @cask_files = nil
     @cask_files_by_name = nil
+    @cask_reverse_renames = nil
     @alias_dir = nil
     @alias_files = nil
     @aliases = nil
@@ -784,10 +785,12 @@ class Tap
     end
   end
 
-  # Hash with tap formula old names. Reverse of {#formula_renames}.
+  # Mapping from new to old cask tokens. Reverse of {#cask_renames}.
+  #
+  # @private
   sig { returns(T::Hash[String, T::Array[String]]) }
-  def reverse_cask_renames
-    @reverse_cask_renames ||= cask_renames.each_with_object({}) do |(old_name, new_name), hash|
+  def cask_reverse_renames
+    @cask_reverse_renames ||= cask_renames.each_with_object({}) do |(old_name, new_name), hash|
       hash[new_name] ||= []
       hash[new_name] << old_name
     end