diff --git a/registration/models.py b/registration/models.py
index 0022696..dbef800 100644
--- a/registration/models.py
+++ b/registration/models.py
@@ -225,9 +225,9 @@ class ParticipantRegistration(Registration):
         if self.team and self.team.participation.tournament:
             important_date = self.team.participation.tournament.date_start
         birth_date = self.birth_date
-        if self.birth_date.month == 2 and self.birth_date.day == 29:
+        if birth_date.month == 2 and birth_date.day == 29:
             # If the birth date is the 29th of February, we consider it as the 1st of March
-            birth_date = important_date.replace(month=3, day=1)
+            birth_date = birth_date.replace(month=3, day=1)
         over_18_on = birth_date.replace(year=birth_date.year + 18)
         return important_date < over_18_on
 
@@ -237,9 +237,10 @@ class ParticipantRegistration(Registration):
             return False  # In normal case
         from participation.models import Tournament
         important_date = Tournament.final_tournament().date_start
-        if self.birth_date.month == 2 and self.birth_date.day == 29:
+        birth_date = self.birth_date
+        if birth_date.month == 2 and birth_date.day == 29:
             # If the birth date is the 29th of February, we consider it as the 1st of March
-            birth_date = important_date.replace(month=3, day=1)
+            birth_date = birth_date.replace(month=3, day=1)
         over_18_on = birth_date.replace(year=birth_date.year + 18)
         return important_date < over_18_on