diff --git a/prospect_trace.py b/prospect_trace.py
index 98f3bdc..a84d49f 100644
--- a/prospect_trace.py
+++ b/prospect_trace.py
@@ -11,7 +11,7 @@ class ProspectTrace(ModelSQL, ModelView):
     'Seguimiento de un prospecto'
     __name__ = 'sale.prospect_trace'
 
-    prospect = fields.Many2One('sale.prospect', 'Prospect')
+    prospect = fields.Many2One('sale.prospect', 'Prospect', required=True)
     prospect_contact = fields.Many2One(
         'prospect.contact_method', 'Contact method')
     prospect_city = fields.Many2One('sale.city', 'City')
diff --git a/tests/test_module.py b/tests/test_module.py
index d478061..96e7972 100644
--- a/tests/test_module.py
+++ b/tests/test_module.py
@@ -1,10 +1,16 @@
-
-from trytond.tests.test_tryton import ModuleTestCase
+from trytond.tests.test_tryton import ModuleTestCase, with_transaction
+from trytond.pool import Pool
 
 
 class SaleOpportunityManagementTestCase(ModuleTestCase):
     "Test Sale Opportunity Management module"
     module = 'sale_opportunity_management'
 
+    @with_transaction()
+    def test_prospecto_en_prospect_trace_es_obligatorio(self):
+        pool = Pool()
+        ProspectTrace = pool.get('sale.prospect_trace')
+        self.assertTrue(ProspectTrace.prospect.required)
+
 
 del ModuleTestCase