diff --git a/src/services/scheduler_sync/discord_events.py b/src/services/scheduler_sync/discord_events.py
index 39e2827..a062af5 100644
--- a/src/services/scheduler_sync/discord_events.py
+++ b/src/services/scheduler_sync/discord_events.py
@@ -2,7 +2,7 @@ from typing import Self
 from datetime import datetime, timedelta
 
 from httpx import AsyncClient
-from pydantic import BaseModel, field_serializer
+from pydantic import BaseModel, field_serializer, SerializationInfo
 
 from config import config
 
@@ -16,7 +16,7 @@ class RecurrenceRule(BaseModel):
     frequency: int
 
     @field_serializer("start", when_used="always")
-    def serialize_datetime(self, value: datetime) -> str:
+    def serialize_datetime(self, value: datetime, info: SerializationInfo) -> str:
         return value.isoformat()
 
     def next_date(self, start: datetime) -> datetime:
@@ -82,7 +82,7 @@ class CreateDiscordEvent(BaseModel):
     recurrence_rule: RecurrenceRule | None
 
     @field_serializer("scheduled_start_time", "scheduled_end_time", when_used="always")
-    def serialize_datetime(self, value: datetime) -> str:
+    def serialize_datetime(self, value: datetime, info: SerializationInfo) -> str:
         return value.isoformat()
 
     @classmethod
@@ -135,7 +135,7 @@ class UpdateDiscordEvent(BaseModel):
     recurrence_rule: RecurrenceRule | None
 
     @field_serializer("scheduled_start_time", "scheduled_end_time", when_used="always")
-    def serialize_datetime(self, value: datetime) -> str:
+    def serialize_datetime(self, value: datetime, info: SerializationInfo) -> str:
         return value.isoformat()