diff --git a/core/oidc/userinfo.py b/core/oidc/userinfo.py
index 70402e7..bdd45d0 100644
--- a/core/oidc/userinfo.py
+++ b/core/oidc/userinfo.py
@@ -6,7 +6,7 @@ def userinfo(claims, user):
     claims['nickname'] = user.profile.nickname
     claims['preferred_username'] = user.profile.preferred_username
     claims['website'] = user.profile.website
-    claims['zoneinfo'] = user.profile.zoneinfo
+    claims['zoneinfo'] = str(user.profile.zoneinfo)
     claims['phone_number'] = user.profile.phone_number
     claims['phone_number_verified'] = user.profile.phone_number_verified
     return claims
\ No newline at end of file