diff --git a/lib/rubygems/package.rb b/lib/rubygems/package.rb
index 13eb25bd26..9b1cb3a142 100644
--- a/lib/rubygems/package.rb
+++ b/lib/rubygems/package.rb
@@ -332,7 +332,16 @@ EOM
 
         FileUtils.rm_rf destination
 
-        FileUtils.mkdir_p File.dirname destination
+        mkdir_options = {}
+        mkdir_options[:mode] = entry.header.mode if entry.directory?
+        mkdir =
+          if entry.directory? then
+            destination
+          else
+            File.dirname destination
+          end
+
+        mkdir_p_safe mkdir, mkdir_options, destination_dir, entry.full_name
 
         open destination, 'wb', entry.header.mode do |out|
           out.write entry.read
@@ -367,12 +376,9 @@ EOM
     raise Gem::Package::PathError.new(filename, destination_dir) if
       filename.start_with? '/'
 
-    destination_dir = File.realpath destination_dir if
-      File.respond_to? :realpath
+    destination_dir = realpath destination_dir
 
     destination = File.join destination_dir, filename
-    destination = File.realpath destination if
-      File.respond_to? :realpath
     destination = File.expand_path destination
 
     raise Gem::Package::PathError.new(destination, destination_dir) unless
@@ -382,6 +388,22 @@ EOM
     destination
   end
 
+  def mkdir_p_safe mkdir, mkdir_options, destination_dir, file_name
+    destination_dir = realpath File.expand_path(destination_dir)
+    parts = mkdir.split(File::SEPARATOR)
+    parts.reduce do |path, basename|
+      path = realpath path  unless path == ""
+      path = File.expand_path(path + File::SEPARATOR + basename)
+      lstat = File.lstat path rescue nil
+      if !lstat || !lstat.directory?
+        unless path.start_with? destination_dir and (FileUtils.mkdir path, mkdir_options rescue false)
+          raise Gem::Package::PathError.new(file_name, destination_dir)
+        end
+      end
+      path
+    end
+  end
+
   ##
   # Loads a Gem::Specification from the TarEntry +entry+
 
@@ -560,6 +582,16 @@ EOM
     raise Gem::Package::FormatError.new(e.message, entry.full_name)
   end
 
+  if File.respond_to? :realpath
+    def realpath file
+      File.realpath file
+    end
+  else
+    def realpath file
+      file
+    end
+  end
+
 end
 
 require 'rubygems/package/digest_io'
-- 
2.20.1