diff --git a/Library/Homebrew/cask/lib/hbc.rb b/Library/Homebrew/cask/lib/hbc.rb
index 3cdec07d22..363879574d 100644
--- a/Library/Homebrew/cask/lib/hbc.rb
+++ b/Library/Homebrew/cask/lib/hbc.rb
@@ -1,6 +1,6 @@
-module Hbc; end
-
 require "hardware"
+require "utils"
+
 require "hbc/artifact"
 require "hbc/audit"
 require "hbc/auditor"
@@ -34,7 +34,6 @@ require "hbc/url_checker"
 require "hbc/utils"
 require "hbc/verify"
 require "hbc/version"
-require "utils"
 
 module Hbc
   include Locations
diff --git a/Library/Homebrew/cask/lib/hbc/cli/list.rb b/Library/Homebrew/cask/lib/hbc/cli/list.rb
index e100fbd833..5d7a58b936 100644
--- a/Library/Homebrew/cask/lib/hbc/cli/list.rb
+++ b/Library/Homebrew/cask/lib/hbc/cli/list.rb
@@ -83,7 +83,7 @@ module Hbc
       end
 
       def self.needs_init?
-        false
+        true
       end
     end
   end
diff --git a/Library/Homebrew/cask/lib/hbc/locations.rb b/Library/Homebrew/cask/lib/hbc/locations.rb
index 7a0f938514..80add91dd5 100644
--- a/Library/Homebrew/cask/lib/hbc/locations.rb
+++ b/Library/Homebrew/cask/lib/hbc/locations.rb
@@ -7,35 +7,10 @@ module Hbc
     end
 
     module ClassMethods
-      def legacy_caskroom
-        @legacy_caskroom ||= Pathname.new("/opt/homebrew-cask/Caskroom")
-      end
-
-      def default_caskroom
-        @default_caskroom ||= HOMEBREW_PREFIX.join("Caskroom")
-      end
-
       attr_writer :caskroom
 
       def caskroom
-        @caskroom ||= begin
-          if Utils.path_occupied?(legacy_caskroom)
-            opoo <<-EOS.undent
-              The default Caskroom location has moved to #{default_caskroom}.
-
-              Please migrate your Casks to the new location and delete #{legacy_caskroom},
-              or if you would like to keep your Caskroom at #{legacy_caskroom}, add the
-              following to your HOMEBREW_CASK_OPTS:
-
-                --caskroom=#{legacy_caskroom}
-
-              For more details on each of those options, see https://github.com/caskroom/homebrew-cask/issues/21913.
-            EOS
-            legacy_caskroom
-          else
-            default_caskroom
-          end
-        end
+        @caskroom ||= HOMEBREW_PREFIX.join("Caskroom")
       end
 
       attr_writer :cache
diff --git a/Library/Homebrew/cask/lib/hbc/url.rb b/Library/Homebrew/cask/lib/hbc/url.rb
index c09aaa0615..1a5101da1f 100644
--- a/Library/Homebrew/cask/lib/hbc/url.rb
+++ b/Library/Homebrew/cask/lib/hbc/url.rb
@@ -29,11 +29,8 @@ module Hbc
     end
 
     def user_agent
-      if @user_agent == :fake
-        FAKE_USER_AGENT
-      else
-        @user_agent
-      end
+      return FAKE_USER_AGENT if @user_agent == :fake
+      @user_agent
     end
   end
 end
diff --git a/Library/Homebrew/compat/hbc.rb b/Library/Homebrew/compat/hbc.rb
index e60bdbc07a..353a72488e 100644
--- a/Library/Homebrew/compat/hbc.rb
+++ b/Library/Homebrew/compat/hbc.rb
@@ -9,7 +9,9 @@ module Hbc
       Module.new do
         def init
           Cache.delete_legacy_cache
+
           Caskroom.migrate_caskroom_from_repo_to_prefix
+          Caskroom.migrate_legacy_caskroom
 
           super
         end
diff --git a/Library/Homebrew/compat/hbc/caskroom.rb b/Library/Homebrew/compat/hbc/caskroom.rb
index 489c5b224a..3621a35fb0 100644
--- a/Library/Homebrew/compat/hbc/caskroom.rb
+++ b/Library/Homebrew/compat/hbc/caskroom.rb
@@ -2,6 +2,31 @@ module Hbc
   module Caskroom
     module_function
 
+    def migrate_legacy_caskroom
+      return if Hbc.caskroom.exist?
+
+      legacy_caskroom = Pathname.new("/opt/homebrew-cask/Caskroom")
+      return if Hbc.caskroom == legacy_caskroom
+      return unless legacy_caskroom.exist?
+      return if legacy_caskroom.symlink?
+
+      ohai "Migrating Caskroom from #{legacy_caskroom} to #{Hbc.caskroom}."
+      if Hbc.caskroom.parent.writable?
+        FileUtils.mv legacy_caskroom, Hbc.caskroom
+      else
+        opoo "#{Hbc.caskroom.parent} is not writable, sudo is needed to move the Caskroom."
+        SystemCommand.run("/bin/mv", args: [legacy_caskroom, Hbc.caskroom.parent], sudo: true)
+      end
+
+      ohai "Creating symlink from #{Hbc.caskroom} to #{legacy_caskroom}."
+      if legacy_caskroom.parent.writable?
+        FileUtils.ln_s Hbc.caskroom, legacy_caskroom
+      else
+        opoo "#{legacy_caskroom.parent} is not writable, sudo is needed to link the Caskroom."
+        SystemCommand.run("/bin/ln", args: ["-s", Hbc.caskroom, legacy_caskroom], sudo: true)
+      end
+    end
+
     def migrate_caskroom_from_repo_to_prefix
       repo_caskroom = HOMEBREW_REPOSITORY.join("Caskroom")
       return if Hbc.caskroom.exist?