diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 40a2aa440f..ec08dd939e 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -15073,8 +15073,8 @@ qemuDomainSnapshotDiskDataCollect(virQEMUDriverPtr driver,
         if (snapdef->disks[i].snapshot == VIR_DOMAIN_SNAPSHOT_LOCATION_NONE)
             continue;
 
-        ndata++;
         dd = data + ndata;
+        ndata++;
 
         dd->disk = vm->def->disks[i];