diff --git a/module.nix b/module.nix
index 0330774..7960a24 100644
--- a/module.nix
+++ b/module.nix
@@ -144,7 +144,7 @@ in
           OIDC_ISSUER = issuer;
           OIDC_DISCOVERY = "true";
           OIDC_SCOPE = "openid,profile";
-          OIDC_UID_FIELD = "sub";
+          OIDC_UID_FIELD = "preferred_username";
           OIDC_CLIENT_ID = oauthClientID;
           OIDC_REDIRECT_URI = oauthRedirectURL;
           OIDC_SECURITY_ASSUME_EMAIL_IS_VERIFIED = "true";