diff --git a/app/controllers/attachments_controller.rb b/app/controllers/attachments_controller.rb
index 8e28194a3..91cd7ce41 100644
--- a/app/controllers/attachments_controller.rb
+++ b/app/controllers/attachments_controller.rb
@@ -105,7 +105,7 @@ class AttachmentsController < ApplicationController
       return
     end
 
-    @attachment = Attachment.new(:file => request.body)
+    @attachment = Attachment.new(:file => raw_request_body)
     @attachment.author = User.current
     @attachment.filename = params[:filename].presence || Redmine::Utils.random_hex(16)
     @attachment.content_type = params[:content_type].presence
@@ -303,4 +303,14 @@ class AttachmentsController < ApplicationController
   def update_all_params
     params.permit(:attachments => [:filename, :description]).require(:attachments)
   end
+
+  # Get an IO-like object for the request body which is usable to create a new
+  # attachment. We try to avoid having to read the whole body into memory.
+  def raw_request_body
+    if request.body.respond_to?(:size)
+      request.body
+    else
+      request.raw_post
+    end
+  end
 end
diff --git a/test/integration/api_test/attachments_test.rb b/test/integration/api_test/attachments_test.rb
index 538649950..1589e3f72 100644
--- a/test/integration/api_test/attachments_test.rb
+++ b/test/integration/api_test/attachments_test.rb
@@ -272,4 +272,29 @@ class Redmine::ApiTest::AttachmentsTest < Redmine::ApiTest::Base
     assert_equal 12, attachment.filesize
     assert File.exist? attachment.diskfile
   end
+
+  test "POST /uploads.json should be compatible with a uwsgi's input" do
+    set_tmp_attachments_directory
+    assert_difference 'Attachment.count' do
+      request_body = Rack::RewindableInput.new(StringIO.new('File content'))
+      # Uwsgi_IO object does not have size method
+      request_body.instance_eval('undef :size', __FILE__, __LINE__)
+      post(
+        '/uploads.json',
+        :headers => {
+          "CONTENT_TYPE" => 'application/octet-stream',
+          "CONTENT_LENGTH" => '12',
+          "rack.input" => request_body
+        }.merge(credentials('jsmith'))
+      )
+      assert_response :created
+    end
+    json = ActiveSupport::JSON.decode(response.body)
+    assert_kind_of Hash, json['upload']
+    token = json['upload']['token']
+    assert token.present?
+    assert attachment = Attachment.find_by_token(token)
+    assert_equal 12, attachment.filesize
+    assert File.exist? attachment.diskfile
+  end
 end