diff --git a/call.py b/call.py
index 25c69d1..73955a0 100644
--- a/call.py
+++ b/call.py
@@ -12,16 +12,20 @@ class Call(ModelSQL, ModelView):
 
     __name__ = 'sale.call'
 
-    date = fields.Date('Date')
+    _states = {'readonly': True}
+
+    date = fields.Date('Date', states=_states)
     description = fields.Text('Description', strip=True)
 
     prospect_trace = fields.Many2One('sale.prospect_trace', 'Prospect trace')
 
     interest = fields.Selection(
         Interest.get_interest_levels(), 'Interest', required=True)
-    call_type = fields.Selection(CallTypes.get_call_types(), 'Call type')
+    call_type = fields.Selection(
+        CallTypes.get_call_types(), 'Call type', states=_states)
     call_result = fields.Selection(
-        CallResults.get_call_results(), 'Call result')
+        CallResults.get_call_results(),
+        'Call result', states=_states)
 
     @classmethod
     def default_date(cls):
diff --git a/prospect_trace.py b/prospect_trace.py
index 49974df..358700d 100644
--- a/prospect_trace.py
+++ b/prospect_trace.py
@@ -11,24 +11,28 @@ class ProspectTrace(DeactivableMixin, ModelSQL, ModelView):
     'Seguimiento de un prospecto'
     __name__ = 'sale.prospect_trace'
 
+    _states = {'readonly': True}
+
     prospect = fields.Many2One('sale.prospect', 'Prospect', required=True)
     prospect_contact = fields.Many2One(
         'prospect.contact_method', 'Contact method')
     prospect_city = fields.Many2One('sale.city', 'City',
-                                    states={'readonly': True})
+                                    states=_states)
 
     calls = fields.One2Many('sale.call', 'prospect_trace', 'Calls')
     pending_call = fields.Many2One('sale.pending_call', 'Pending call')
 
     current_interest = fields.Selection(
-        Interest.get_interest_levels(), 'Current interest')
+        Interest.get_interest_levels(), 'Current interest',
+        states=_states)
 
     state = fields.Selection([
             ('unassigned', 'Unassigned'),
             ('open', 'Open'),
             ('with_pending_calls', 'With pending calls'),
             ('closed', 'Closed')
-            ], 'State')
+            ], 'State',
+            states=_states)
 
     @classmethod
     def default_state(cls):