diff --git a/pycroft/lib/swdd.py b/pycroft/lib/swdd.py
index c8e3b90d8..dcfd6fb97 100644
--- a/pycroft/lib/swdd.py
+++ b/pycroft/lib/swdd.py
@@ -5,6 +5,7 @@
 import hmac
 import os
 import unicodedata
+from datetime import date
 
 from sqlalchemy import func
 
@@ -13,7 +14,7 @@
 swdd_hmac_key = os.environ.get('SWDD_HASH_KEY')
 
 
-def get_swdd_person_id(first_name: str, last_name: str, birthdate: str) -> int | None:
+def get_swdd_person_id(first_name: str, last_name: str, birthdate: date) -> int | None:
     """
     Builds a hmac hash from the given parameters and searches for a match in the Tenancy view
 
diff --git a/web/api/v0/__init__.py b/web/api/v0/__init__.py
index 8b7e1ee7f..c8f1e0f81 100644
--- a/web/api/v0/__init__.py
+++ b/web/api/v0/__init__.py
@@ -2,6 +2,7 @@
 from decimal import Decimal
 from datetime import timedelta, datetime, date
 from functools import wraps
+from ipaddress import IPv4Address, IPv6Address
 
 from flask import jsonify, current_app, Response
 from flask.typing import ResponseReturnValue
@@ -529,7 +530,7 @@ class RegistrationResource(Resource):
         {
             "first_name": fields.Str(required=True),
             "last_name": fields.Str(required=True),
-            "birthdate": fields.Str(required=True),
+            "birthdate": fields.Date(required=True),
             "person_id": fields.Int(required=True),
             "previous_dorm": fields.Str(required=False),
         },
@@ -539,7 +540,7 @@ def get(
         self,
         first_name: str,
         last_name: str,
-        birthdate: str,
+        birthdate: date,
         person_id: int,
         previous_dorm: str | None = None,
     ) -> ResponseReturnValue:
@@ -607,7 +608,7 @@ def get(
         {
             "first_name": fields.Str(required=True),
             "last_name": fields.Str(required=False),
-            "birthdate": fields.Str(required=True),
+            "birthdate": fields.Date(required=True),
             "email": fields.Str(required=True),
             "password": fields.Str(required=True),
             "login": fields.Str(required=True),
@@ -621,7 +622,7 @@ def get(
     def post(
         self,
         first_name: str,
-        birthdate: str,
+        birthdate: date,
         email: str,
         password: str,
         login: str,