diff --git a/modules/grist.nix b/modules/grist.nix
index 6172cc2..75391e5 100644
--- a/modules/grist.nix
+++ b/modules/grist.nix
@@ -25,7 +25,7 @@ with lib;
           image = "docker.io/gristlabs/grist:latest";
           environment = {
             # The URL of given OIDC provider. Used for redirects, among other things.
-            GRIST_OIDC_IDP_ISSUER = "https://${auth_dn}";
+            GRIST_OIDC_IDP_ISSUER = "https://${auth_dn}/authorize";
             # Client ID, as configured with the OIDC provider.
             GRIST_OIDC_IDP_CLIENT_ID = "LtgrHHZmKucQAZtYNZGrirxdEru5pWByaJQcEfiufcitd0kfi2qVjuU6gPZE4haz";
             # Client secret, as provided by the OIDC provider.