diff --git a/seminar/migrations/0019_rocnik_ciselne.py b/seminar/migrations/0019_rocnik_ciselne.py
new file mode 100644
index 00000000..42308b2f
--- /dev/null
+++ b/seminar/migrations/0019_rocnik_ciselne.py
@@ -0,0 +1,32 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import models, migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('seminar', '0018_problemnavrh_problemzadany'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='rocnik',
+            name='rocnik_n',
+            field=models.IntegerField(default=0, verbose_name='\u010d\xedslo ro\u010dn\xedku'),
+            preserve_default=False,
+        ),
+        migrations.RunSQL(
+            sql="update seminar_rocniky set rocnik_n = cast (rocnik as integer)"
+        ),
+        migrations.RemoveField(
+            model_name='rocnik',
+            name='rocnik',
+        ),
+        migrations.RenameField(
+            model_name='rocnik',
+            old_name='rocnik_n',
+            new_name='rocnik',
+        ),
+    ]
diff --git a/seminar/models.py b/seminar/models.py
index 62529835..acd0a89b 100644
--- a/seminar/models.py
+++ b/seminar/models.py
@@ -204,16 +204,13 @@ class Rocnik(SeminarModelBase):
 
     prvni_rok = models.IntegerField(u'první rok')
 
-    rocnik = models.CharField(u'číslo ročníku', max_length=16)
+    rocnik = models.IntegerField(u'číslo ročníku')
 
     def __str__(self):
         return force_unicode(u'%s (%d/%d)' % (self.rocnik, self.prvni_rok, self.prvni_rok+1))
 
     def roman(self):
-        if self.rocnik.isdigit():
-            return force_unicode(roman(int(self.rocnik)))
-        else:
-            return force_unicode(self.rocnik)
+        return force_unicode(roman(int(self.rocnik)))
 
     def verejne(self):
         return len(self.verejna_cisla()) > 0