diff --git a/conntrackt/tests/test_models.py b/conntrackt/tests/test_models.py
--- a/conntrackt/tests/test_models.py
+++ b/conntrackt/tests/test_models.py
@@ -117,6 +117,18 @@ class EntityTest(TestCase):
 
         self.assertEqual(entity.get_absolute_url(), "/conntrackt/entity/1/")
 
+    def test_project_move_constraints(self):
+        """
+        Tests if entity is prevented from being moved to different project in
+        case of existing communications.
+        """
+
+        entity = Entity.objects.get(pk=1)
+        new_project = Project.objects.get(pk=2)
+
+        entity.project = new_project
+        self.assertRaisesRegexp(ValidationError, "The entity cannot be moved to different project as long as it has valid communications with entities in current project." ,entity.clean)
+
 
 class InterfaceTest(TestCase):
     fixtures = ['test-data.json']