diff --git a/seminar/models.py b/seminar/models.py
index 45e5885e..67faff22 100644
--- a/seminar/models.py
+++ b/seminar/models.py
@@ -607,7 +607,7 @@ class Problem(SeminarModelBase,PolymorphicModel):
 
 	# Problém má podproblémy
 	nadproblem = models.ForeignKey('self', verbose_name='nadřazený problém',
-		related_name='podproblem', null=True, blank=True,
+		related_name='podproblem_%(class)s', null=True, blank=True,
 		on_delete=models.SET_NULL)
 
 	STAV_NAVRH = 'navrh'