diff --git a/Library/Homebrew/cask/cask.rb b/Library/Homebrew/cask/cask.rb
index 955cad92df..6bfc198f74 100644
--- a/Library/Homebrew/cask/cask.rb
+++ b/Library/Homebrew/cask/cask.rb
@@ -96,7 +96,7 @@ module Cask
 
         MacOSVersions::SYMBOLS.each do |os_name, os_version|
           MacOS.full_version = os_version
-          cask = CaskLoader.load(token)
+          cask = CaskLoader.load(full_name)
           version_os_hash[os_name] = cask.version if cask.version != version
         end
 
diff --git a/Library/Homebrew/cask/cask_loader.rb b/Library/Homebrew/cask/cask_loader.rb
index cb6aefb10d..8049077ee6 100644
--- a/Library/Homebrew/cask/cask_loader.rb
+++ b/Library/Homebrew/cask/cask_loader.rb
@@ -236,9 +236,7 @@ module Cask
       when 2..Float::INFINITY
         loaders = possible_tap_casks.map(&FromTapPathLoader.method(:new))
 
-        raise TapCaskAmbiguityError.new(ref, loaders) if loaders.map(&:tap).map(&:name).uniq.size == 1
-
-        return FromTapPathLoader.new(possible_tap_casks.first)
+        raise TapCaskAmbiguityError.new(ref, loaders)
       end
 
       possible_installed_cask = Cask.new(ref)