diff --git a/app/schemas/base_schemas.py b/app/schemas/base_schemas.py
index 2ade802..03af8da 100644
--- a/app/schemas/base_schemas.py
+++ b/app/schemas/base_schemas.py
@@ -17,7 +17,7 @@ class User(BaseModel):
     registration_date: str
 
 class Card(BaseModel):
-    card_id: ObjectId = Field(alias="_id")
+    card_id: ObjectId = Field(alias="_id", default=ObjectId())
 
     choice_A: str
     choice_B: str