diff --git a/hw/pci_host.c b/hw/pci_host.c
index 44c6c207a9fc1ebd23f3de795efe8fbec0bd38f5..804177891a6e36f801ed5a8d68e62a8b468fb534 100644
--- a/hw/pci_host.c
+++ b/hw/pci_host.c
@@ -101,6 +101,9 @@ static void pci_host_config_write(void *opaque, target_phys_addr_t addr,
 
     PCI_DPRINTF("%s addr " TARGET_FMT_plx " len %d val %"PRIx64"\n",
                 __func__, addr, len, val);
+    if (addr != 0 || len != 4) {
+        return;
+    }
     s->config_reg = val;
 }