diff --git a/rust/qemu-api/src/vmstate.rs b/rust/qemu-api/src/vmstate.rs
index 9533b1250f..e3233303f2 100644
--- a/rust/qemu-api/src/vmstate.rs
+++ b/rust/qemu-api/src/vmstate.rs
@@ -275,6 +275,7 @@ impl VMStateField {
         assert!((self.flags.0 & VMStateFlags::VMS_ARRAY.0) != 0);
         self.flags = VMStateFlags(self.flags.0 & !VMStateFlags::VMS_ARRAY.0);
         self.flags = VMStateFlags(self.flags.0 | flag.0);
+        self.num = 0; // varray uses num_offset instead of num.
         self
     }