diff --git a/tools/virsh-domain.c b/tools/virsh-domain.c
index 545ebe26b6..cc8a3dff50 100644
--- a/tools/virsh-domain.c
+++ b/tools/virsh-domain.c
@@ -7941,8 +7941,10 @@ vshPrepareDiskXML(xmlNodePtr disk_node,
 
             if (source) {
                 new_node = xmlNewNode(NULL, BAD_CAST "source");
-                xmlNewProp(new_node, (const xmlChar *)disk_type,
-                           (const xmlChar *)source);
+                if (STREQ(disk_type, "block"))
+                    xmlNewProp(new_node, BAD_CAST "dev", BAD_CAST source);
+                else
+                    xmlNewProp(new_node, BAD_CAST disk_type, BAD_CAST source);
                 xmlAddChild(disk_node, new_node);
             } else if (type == VSH_PREPARE_DISK_XML_INSERT) {
                 vshError(NULL, _("No source is specified for inserting media"));