diff --git a/jdav_web/logindata/oauth.py b/jdav_web/logindata/oauth.py
index 06d870b..ee0e5f3 100644
--- a/jdav_web/logindata/oauth.py
+++ b/jdav_web/logindata/oauth.py
@@ -6,6 +6,8 @@ class CustomOAuth2Validator(OAuth2Validator):
     # otherwise the OIDC standard scopes are used.
 
     def get_additional_claims(self, request):
-        return {
-            "preferred_username": request.user.username
-        }
+        if request.user.member:
+            context = {'email': request.user.member.email}
+        else:
+            context = {}
+        return dict(context, preferred_username=request.user.username)