diff --git a/app/models/merge_request.rb b/app/models/merge_request.rb
index df162e4844c..311ba1ce6bd 100644
--- a/app/models/merge_request.rb
+++ b/app/models/merge_request.rb
@@ -581,6 +581,8 @@ class MergeRequest < ApplicationRecord
   end
 
   def validate_branches
+    return unless target_project && source_project
+
     if target_project == source_project && target_branch == source_branch
       errors.add :branch_conflict, "You can't use same project/branch for source and target"
       return
diff --git a/spec/models/deployment_spec.rb b/spec/models/deployment_spec.rb
index f51322e1404..1dceef3fc00 100644
--- a/spec/models/deployment_spec.rb
+++ b/spec/models/deployment_spec.rb
@@ -5,8 +5,8 @@ require 'spec_helper'
 describe Deployment do
   subject { build(:deployment) }
 
-  it { is_expected.to belong_to(:project) }
-  it { is_expected.to belong_to(:environment) }
+  it { is_expected.to belong_to(:project).required }
+  it { is_expected.to belong_to(:environment).required }
   it { is_expected.to belong_to(:user) }
   it { is_expected.to belong_to(:deployable) }
 
diff --git a/spec/models/environment_spec.rb b/spec/models/environment_spec.rb
index 17246f238e0..7233d2454c6 100644
--- a/spec/models/environment_spec.rb
+++ b/spec/models/environment_spec.rb
@@ -6,7 +6,7 @@ describe Environment do
   let(:project) { create(:project, :stubbed_repository) }
   subject(:environment) { create(:environment, project: project) }
 
-  it { is_expected.to belong_to(:project) }
+  it { is_expected.to belong_to(:project).required }
   it { is_expected.to have_many(:deployments) }
 
   it { is_expected.to delegate_method(:stop_action).to(:last_deployment) }