diff --git a/hw/vfio/iommufd.c b/hw/vfio/iommufd.c
index a108beda29e248b4188ba2c74db915f54865e854..6fc4f3ab398b5807302abee4e552f667c327b893 100644
--- a/hw/vfio/iommufd.c
+++ b/hw/vfio/iommufd.c
@@ -541,8 +541,8 @@ static int iommufd_cdev_attach(const char *name, VFIODevice *vbasedev,
         } else {
             ret = iommufd_cdev_ram_block_discard_disable(true);
             if (ret) {
-                error_setg(errp,
-                              "Cannot set discarding of RAM broken (%d)", ret);
+                error_setg_errno(errp, -ret,
+                                 "Cannot set discarding of RAM broken");
                 goto err_discard_disable;
             }
             goto found_container;
@@ -573,6 +573,7 @@ static int iommufd_cdev_attach(const char *name, VFIODevice *vbasedev,
 
     ret = iommufd_cdev_ram_block_discard_disable(true);
     if (ret) {
+        error_setg_errno(errp, -ret, "Cannot set discarding of RAM broken");
         goto err_discard_disable;
     }