diff --git a/prospect.py b/prospect.py
index a0c0e3c..af2310e 100644
--- a/prospect.py
+++ b/prospect.py
@@ -39,6 +39,8 @@ class Prospect(ModelSQL, ModelView):
     def on_change_assigned_operator(self):
         if self.assigned_operator:
             self.state = 'assigned'
+        else:
+            self.state = 'unassigned'
 
 
 class ContactMethod(ModelSQL, ModelView):
diff --git a/tests/scenario_sale_opportunity_management.rst b/tests/scenario_sale_opportunity_management.rst
index 75de79f..f61ab94 100644
--- a/tests/scenario_sale_opportunity_management.rst
+++ b/tests/scenario_sale_opportunity_management.rst
@@ -86,7 +86,13 @@ Asignar operario a un prospecto::
     'Administrator'
     >>> prospect.state
     'assigned'
-  
+
+Remover operario asignado de un prospecto::
+    >>> prospect.assigned_operator = None
+    >>> prospect.state
+    'unassigned'
+
+
 ------------------------------------
 Asignación de prospectos a operarios
 ------------------------------------