diff --git a/lib/fileutils.rb b/lib/fileutils.rb
index 0a48c03..a9c4a76 100644
--- a/lib/fileutils.rb
+++ b/lib/fileutils.rb
@@ -2467,12 +2467,6 @@ def join(dir, base)
       end
     end
 
-    if File::ALT_SEPARATOR
-      DIRECTORY_TERM = "(?=[/#{Regexp.quote(File::ALT_SEPARATOR)}]|\\z)"
-    else
-      DIRECTORY_TERM = "(?=/|\\z)"
-    end
-
     def descendant_directory?(descendant, ascendant)
       if File::FNM_SYSCASE.nonzero?
         File.expand_path(File.dirname(descendant)).casecmp(File.expand_path(ascendant)) == 0