diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c
index 1728e4f83a..a12677d4d5 100644
--- a/hw/virtio/virtio-balloon.c
+++ b/hw/virtio/virtio-balloon.c
@@ -311,7 +311,7 @@ out:
 static void virtio_balloon_get_config(VirtIODevice *vdev, uint8_t *config_data)
 {
     VirtIOBalloon *dev = VIRTIO_BALLOON(vdev);
-    struct virtio_balloon_config config;
+    struct virtio_balloon_config config = {};
 
     config.num_pages = cpu_to_le32(dev->num_pages);
     config.actual = cpu_to_le32(dev->actual);