diff --git a/subjects/forms.py b/subjects/forms.py
index cfd0e78..f21d653 100644
--- a/subjects/forms.py
+++ b/subjects/forms.py
@@ -4,9 +4,19 @@ import datetime
 from .models import Subject, Tag
 
 class CreateSubjectForm(forms.ModelForm):
+    category_id = None
+
     def __init__(self, *args, **kwargs):
         super(CreateSubjectForm, self).__init__(*args, **kwargs)
 
+        if kwargs['initial']:
+            if kwargs['initial']['category']:
+                categories = kwargs['initial']['category']
+
+                if categories.count() > 0:
+                    self.category_id = categories[0].id
+
+
         if not kwargs['instance'] is None:
             self.initial['tags'] = ", ".join(self.instance.tags.all().values_list("name", flat = True))
 
@@ -58,15 +68,16 @@ class CreateSubjectForm(forms.ModelForm):
 
     def clean_name(self):
         name = self.cleaned_data.get('name')
-        categoria = self.instance.category
+        
         if self.instance.id:
-            same_name = Subject.objects.filter(name__unaccent__iexact = name, category = categoria).exclude(id = self.instance.id)
+            same_name = Subject.objects.filter(name__unaccent__iexact = name, category = self.category_id).exclude(id = self.instance.id)
         else:
-            same_name = Subject.objects.filter(name__unaccent__iexact = name, category = categoria)
+            same_name = Subject.objects.filter(name__unaccent__iexact = name, category = self.category_id)
+        
         if same_name.count() > 0:
             self._errors['name'] = [_('There is another subject with this name, try another one.')]
-
-
+            return ValueError
+        
         return name
 
     def clean_subscribe_begin(self):
@@ -162,14 +173,15 @@ class UpdateSubjectForm(forms.ModelForm):
     def clean_name(self):
         name = self.cleaned_data.get('name')
         categoria = self.instance.category
+        
         if self.instance.id:
             same_name = Subject.objects.filter(name__unaccent__iexact = name , category = categoria).exclude(id = self.instance.id)
         else:
-            same_name = Subject.objects.filter(name__unaccent__iexact = name).exclude(category = categoria)
+            same_name = Subject.objects.filter(name__unaccent__iexact = name, category = categoria)
+        
         if same_name.count() > 0:
             self._errors['name'] = [_('There is another subject with this name, try another one.')]
 
-
         return name
 
     # def clean_subscribe_begin(self):
diff --git a/subjects/migrations/0016_auto_20170831_1327.py b/subjects/migrations/0016_auto_20170831_1327.py
new file mode 100644
index 0000000..10e7cdc
--- /dev/null
+++ b/subjects/migrations/0016_auto_20170831_1327.py
@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.10.4 on 2017-08-31 16:27
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('subjects', '0015_auto_20170815_1203'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='subject',
+            name='name',
+            field=models.CharField(max_length=200, verbose_name='Name'),
+        ),
+    ]
diff --git a/subjects/models.py b/subjects/models.py
index cd35f3f..5cda91f 100644
--- a/subjects/models.py
+++ b/subjects/models.py
@@ -20,7 +20,7 @@ class Tag(models.Model):
 
 class Subject(models.Model):
 
-    name = models.CharField( _("Name"), unique = True,max_length= 200)
+    name = models.CharField( _("Name"), unique = False, max_length= 200)
     slug = AutoSlugField(_("Slug"),populate_from='name',unique=True)
 
     description_brief = models.TextField(_("simpler_description"), blank=True)
--
libgit2 0.21.2