diff --git a/app/controllers/concerns/file_parameters.rb b/app/controllers/concerns/file_parameters.rb
index f816a296..0236b1cb 100644
--- a/app/controllers/concerns/file_parameters.rb
+++ b/app/controllers/concerns/file_parameters.rb
@@ -6,7 +6,7 @@ module FileParameters
       params.reject do |_, file_attributes|
         file = CodeOcean::File.find_by(id: file_attributes[:file_id])
         # avoid that public files from other contexts can be created
-        file.nil? || file.hidden || file.read_only || file.context == 'Exercise' && file.context_id != exercise.id
+        file.nil? || file.hidden || file.read_only || file.context_type == 'Exercise' && file.context_id != exercise.id
       end
     else
       []
diff --git a/spec/concerns/file_parameters_spec.rb b/spec/concerns/file_parameters_spec.rb
index c72e3bd5..73383045 100644
--- a/spec/concerns/file_parameters_spec.rb
+++ b/spec/concerns/file_parameters_spec.rb
@@ -24,7 +24,8 @@ describe FileParameters do
       end
 
       it 'new file' do
-        new_file = FactoryBot.create(:file, context: hello_world)
+        submission = FactoryBot.create(:submission, exercise: hello_world, id: 1337)
+        new_file = FactoryBot.create(:file, context: submission)
         expect(file_accepted?(new_file)).to be true
       end
     end