diff --git a/apps/note/models/transactions.py b/apps/note/models/transactions.py
index 366b4527..c9c6bf69 100644
--- a/apps/note/models/transactions.py
+++ b/apps/note/models/transactions.py
@@ -264,6 +264,17 @@ class SpecialTransaction(Transaction):
     def type(self):
         return _('Credit') if isinstance(self.source, NoteSpecial) else _("Debit")
 
+    def is_credit(self):
+        return isinstance(self.source, NoteSpecial)
+
+    def is_debit(self):
+        return isinstance(self.destination, NoteSpecial)
+
+    def clean(self):
+        # SpecialTransaction are only possible with NoteSpecial object
+        if self.is_credit() == self.is_debit():
+            raise(ValidationError(_("A special transaction is only possible between a  Note associated to a payment method and a User or a Club")))
+
 
 class MembershipTransaction(Transaction):
     """
diff --git a/apps/treasury/models.py b/apps/treasury/models.py
index 5628504b..1e7f2a95 100644
--- a/apps/treasury/models.py
+++ b/apps/treasury/models.py
@@ -191,7 +191,7 @@ class SpecialTransactionProxy(models.Model):
     """
     In order to keep modularity, we don't that the Note app depends on the treasury app.
     That's why we create a proxy in this app, to link special transactions and remittances.
-    If it isn't very clean, that makes what we want.
+    If it isn't very clean, it does what we want.
     """
 
     transaction = models.OneToOneField(
diff --git a/apps/treasury/signals.py b/apps/treasury/signals.py
index 188be1a7..b7038ab6 100644
--- a/apps/treasury/signals.py
+++ b/apps/treasury/signals.py
@@ -1,7 +1,6 @@
 # Copyright (C) 2018-2020 by BDE ENS Paris-Saclay
 # SPDX-License-Identifier: GPL-3.0-or-later
 
-from note.models import NoteSpecial
 from treasury.models import SpecialTransactionProxy, RemittanceType
 
 
@@ -9,6 +8,10 @@ def save_special_transaction(instance, created, **kwargs):
     """
     When a special transaction is created, we create its linked proxy
     """
-    if created and isinstance(instance.source, NoteSpecial) \
-            and RemittanceType.objects.filter(note=instance.source).exists():
-        SpecialTransactionProxy.objects.create(transaction=instance, remittance=None).save()
+
+    if instance.is_credit():
+        if created and RemittanceType.objects.filter(note=instance.source).exists():
+            SpecialTransactionProxy.objects.create(transaction=instance, remittance=None).save()
+    else:
+        if created and RemittanceType.objects.filter(note=instance.destination).exists():
+            SpecialTransactionProxy.objects.create(transaction=instance, remittance=None).save()