diff --git a/backend/app/api/handlers/v1/v1_ctrl_group.go b/backend/app/api/handlers/v1/v1_ctrl_group.go
index 72ce463..0d26869 100644
--- a/backend/app/api/handlers/v1/v1_ctrl_group.go
+++ b/backend/app/api/handlers/v1/v1_ctrl_group.go
@@ -57,7 +57,7 @@ func (ctrl *V1Controller) HandleGroupUpdate() errchain.HandlerFunc {
 		ok := ctrl.svc.Currencies.IsSupported(body.Currency)
 		if !ok {
 			return repo.Group{}, validate.NewFieldErrors(
-				validate.NewFieldError("currency", "currency is not supported"),
+				validate.NewFieldError("currency", "currency '" + body.Currency + "' is not supported"),
 			)
 		}