1 files changed, 13 insertions, 12 deletions
diff --git a/actionpack/lib/action_dispatch/http/upload.rb b/actionpack/lib/action_dispatch/http/upload.rb
index 49465d820e..84e58d7d6a 100644
--- a/actionpack/lib/action_dispatch/http/upload.rb
+++ b/actionpack/lib/action_dispatch/http/upload.rb
@@ -2,27 +2,28 @@ require 'active_support/core_ext/object/blank'
 
 module ActionDispatch
   module Http
-    class UploadedFile < Tempfile
+    class UploadedFile
       attr_accessor :original_filename, :content_type, :tempfile, :headers
 
       def initialize(hash)
         @original_filename = hash[:filename]
         @content_type      = hash[:type]
         @headers           = hash[:head]
+        @tempfile          = hash[:tempfile]
+        raise(ArgumentError, ':tempfile is required') unless @tempfile
+      end
 
-        # To the untrained eye, this may appear as insanity. Given the alternatives,
-        # such as busting the method cache on every request or breaking backwards
-        # compatibility with is_a?(Tempfile), this solution is the best available
-        # option.
-        #
-        # TODO: Deprecate is_a?(Tempfile) and define a real API for this parameter
-        tempfile = hash[:tempfile]
-        tempfile.instance_variables.each do |ivar|
-          instance_variable_set(ivar, tempfile.instance_variable_get(ivar))
-        end
+      def read(*args)
+        @tempfile.read(*args)
       end
 
-      alias local_path path
+      def rewind
+        @tempfile.rewind
+      end
+
+      def size
+        @tempfile.size
+      end
     end
 
     module Upload