diff --git a/app/controllers/remote_evaluation_controller.rb b/app/controllers/remote_evaluation_controller.rb
index 36d61f73..5f01860c 100644
--- a/app/controllers/remote_evaluation_controller.rb
+++ b/app/controllers/remote_evaluation_controller.rb
@@ -15,14 +15,12 @@ class RemoteEvaluationController < ApplicationController
 
     # todo extra: validiere, ob files wirklich zur Übung gehören (wenn allowNewFiles-flag nicht gesetzt ist)
     if (remote_evaluation_mapping = RemoteEvaluationMapping.find_by(:validation_token => validation_token))
-      puts remote_evaluation_mapping.exercise_id
-      puts remote_evaluation_mapping.user_id
 
       _params = remote_evaluation_params.except(:validation_token)
       _params[:exercise_id] = remote_evaluation_mapping.exercise_id
       _params[:user_id] = remote_evaluation_mapping.user_id
       _params[:cause] = "remoteAssess"
-      _params[:user_type] = "ExternalUser"
+      _params[:user_type] = remote_evaluation_mapping.user_type
 
       @submission = Submission.create(_params)
       render json: score_submission(@submission)
diff --git a/app/controllers/submissions_controller.rb b/app/controllers/submissions_controller.rb
index 8d16eb90..32d1e560 100644
--- a/app/controllers/submissions_controller.rb
+++ b/app/controllers/submissions_controller.rb
@@ -398,13 +398,13 @@ class SubmissionsController < ApplicationController
   private :with_server_sent_events
 
   def create_remote_evaluation_mapping
-    user_id = @submission.user_id
+    user = @submission.user
     exercise_id = @submission.exercise_id
 
-    remote_evaluation_mapping = RemoteEvaluationMapping.create(:user_id => user_id, :exercise_id => exercise_id)
+    remote_evaluation_mapping = RemoteEvaluationMapping.create(user: user, exercise_id: exercise_id)
 
     # create .co file
-    path = "tmp/" + user_id.to_s + ".co"
+    path = "tmp/" + user.id.to_s + ".co"
     # parse validation token
     content = "#{remote_evaluation_mapping.validation_token}\n"
     # parse remote request url
diff --git a/app/models/remote_evaluation_mapping.rb b/app/models/remote_evaluation_mapping.rb
index 551ab8a6..a0fba790 100644
--- a/app/models/remote_evaluation_mapping.rb
+++ b/app/models/remote_evaluation_mapping.rb
@@ -2,9 +2,9 @@
 class RemoteEvaluationMapping < ApplicationRecord
   before_create :generate_token, unless: :validation_token?
   belongs_to :exercise
-  belongs_to :user, class_name: 'ExternalUser'
+  belongs_to :user, polymorphic: true
 
   def generate_token
     self.validation_token = SecureRandom.urlsafe_base64
   end
-end
\ No newline at end of file
+end
diff --git a/db/migrate/20181126163428_add_user_type_to_remote_evaluation_mappings.rb b/db/migrate/20181126163428_add_user_type_to_remote_evaluation_mappings.rb
new file mode 100644
index 00000000..0ad50d0f
--- /dev/null
+++ b/db/migrate/20181126163428_add_user_type_to_remote_evaluation_mappings.rb
@@ -0,0 +1,8 @@
+class AddUserTypeToRemoteEvaluationMappings < ActiveRecord::Migration[5.2]
+  def change
+    add_column :remote_evaluation_mappings, :user_type, :string
+    # Update all existing records and set user_type to `ExternalUser` (safe way to prevent any function loss).
+    # We are not using a default value here on intend to be in line with the other `user_type` columns
+    RemoteEvaluationMapping.update_all(user_type: 'ExternalUser')
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index f84e45d1..f918e876 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2018_09_04_115948) do
+ActiveRecord::Schema.define(version: 2018_11_26_163428) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -290,6 +290,7 @@ ActiveRecord::Schema.define(version: 2018_09_04_115948) do
     t.string "validation_token", null: false
     t.datetime "created_at"
     t.datetime "updated_at"
+    t.string "user_type"
   end
 
   create_table "request_for_comments", force: :cascade do |t|