diff --git a/hw/pass-through.c b/hw/pass-through.c
index dbe8804..6a77657 100644
--- a/hw/pass-through.c
+++ b/hw/pass-through.c
@@ -2085,7 +2085,7 @@ struct pci_dev *pt_pci_get_dev(int bus, int dev, int fn)
 
 u32 pt_pci_host_read(struct pci_dev *pci_dev, u32 addr, int len)
 {
-    u32 val = -1;
+    u32 val = 0;
 
     pci_access_init();
     pci_read_block(pci_dev, addr, (u8 *) &val, len);