diff --git a/nixos/modules/services/security/kanidm.nix b/nixos/modules/services/security/kanidm.nix
index 02774fe114da..77aa6bafebab 100644
--- a/nixos/modules/services/security/kanidm.nix
+++ b/nixos/modules/services/security/kanidm.nix
@@ -548,7 +548,7 @@ in
                 description = "The redirect URL of the service. These need to exactly match the OAuth2 redirect target";
                 type =
                   let
-                    originStrType = types.strMatching ".*://.*$";
+                    originStrType = types.strMatching ".*://?.*$";
                   in
                   types.either originStrType (types.nonEmptyListOf originStrType);
                 example = "https://someservice.example.com/auth/login";