diff --git a/app/routers/monitors.py b/app/routers/monitors.py
index 798432e..d72b8db 100644
--- a/app/routers/monitors.py
+++ b/app/routers/monitors.py
@@ -17,7 +17,9 @@ router = APIRouter(prefix="/monitors", tags=["monitors"])
 
 @router.post("/", response_model=MonitorResponse)
 def create_monitor(monitor: MonitorCreate, db: Session = Depends(get_db)):
-    db_monitor = Monitor(**monitor.dict())
+    monitor_data = monitor.dict()
+    monitor_data["url"] = str(monitor_data["url"])  # Convert Pydantic URL to string
+    db_monitor = Monitor(**monitor_data)
     db.add(db_monitor)
     db.commit()
     db.refresh(db_monitor)
@@ -47,6 +49,8 @@ def update_monitor(
         raise HTTPException(status_code=404, detail="Monitor not found")
 
     update_data = monitor.dict(exclude_unset=True)
+    if "url" in update_data:
+        update_data["url"] = str(update_data["url"])  # Convert Pydantic URL to string
     for field, value in update_data.items():
         setattr(db_monitor, field, value)