diff --git a/models.py b/models.py
index 39900c7..42d083a 100644
--- a/models.py
+++ b/models.py
@@ -149,7 +149,7 @@ class UserContainer(db.Model):
     blocked_by = db.Column(db.Integer, db.ForeignKey('user.id', ondelete='SET NULL'), nullable=True)
 
     # Relationships
-    user = db.relationship('User', back_populates='containers')
+    user = db.relationship('User', foreign_keys=[user_id], back_populates='containers')
     blocker = db.relationship('User', foreign_keys=[blocked_by])
 
     # Unique: Ein User kann nur einen Container pro Typ haben