diff --git a/seminar/migrations/0052_user_to_organizator.py b/seminar/migrations/0052_user_to_organizator.py
index 8bdf9ef0..4ebcd1d0 100644
--- a/seminar/migrations/0052_user_to_organizator.py
+++ b/seminar/migrations/0052_user_to_organizator.py
@@ -20,7 +20,7 @@ def spoj_k_organizatorum_osoby(apps, scema_editor):
 		org.osoba = osoba
 
 		# Přesun informací z organizátora do jeho osoby
-		osoba.prezdivka = org.prezdivka
+		osoba.prezdivka = org.prezdivka if org.prezdivka is not None else ''
 		osoba.foto = org.foto
 		
 		# Všechno uložit