diff --git a/block/write-threshold.c b/block/write-threshold.c
index c2cd517..a53c1f5 100644
--- a/block/write-threshold.c
+++ b/block/write-threshold.c
@@ -112,7 +112,7 @@
 
     bs = bdrv_find_node(node_name);
     if (!bs) {
-        error_set(errp, QERR_DEVICE_NOT_FOUND, node_name);
+        error_setg(errp, "Device '%s' not found", node_name);
         return;
     }
 
diff --git a/qapi/block-core.json b/qapi/block-core.json
index 90586a5..42c8850 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -1961,10 +1961,6 @@
 # @write-threshold: configured threshold for the block device, bytes.
 #                   Use 0 to disable the threshold.
 #
-# Returns: Nothing on success
-#          If @node name is not found on the block device graph,
-#          DeviceNotFound
-#
 # Since: 2.3
 ##
 { 'command': 'block-set-write-threshold',