diff --git a/src/qemu/qemu_block.c b/src/qemu/qemu_block.c
index 9d8b3012c7..1eb55315ae 100644
--- a/src/qemu/qemu_block.c
+++ b/src/qemu/qemu_block.c
@@ -1771,14 +1771,15 @@ qemuBlockStorageSourceDetachPrepare(virStorageSource *src)
 
     data = g_new0(qemuBlockStorageSourceAttachData, 1);
 
-    data->formatNodeName = qemuBlockStorageSourceGetFormatNodename(src);
-    data->formatAttached = true;
-    data->storageNodeName = qemuBlockStorageSourceGetStorageNodename(src);
-    data->storageAttached = true;
+    if ((data->formatNodeName = qemuBlockStorageSourceGetFormatNodename(src)))
+        data->formatAttached = true;
 
     if ((data->storageSliceNodeName = qemuBlockStorageSourceGetSliceNodename(src)))
         data->storageSliceAttached = true;
 
+    data->storageNodeName = qemuBlockStorageSourceGetStorageNodename(src);
+    data->storageAttached = true;
+
     if (src->pr &&
         !virStoragePRDefIsManaged(src->pr))
         data->prmgrAlias = g_strdup(src->pr->mgralias);