diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index a9b37f8000..6e7015329c 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -2640,15 +2640,15 @@ static char *pci_dev_fw_name(DeviceState *dev, char *buf, int len)
 static char *pcibus_get_fw_dev_path(DeviceState *dev)
 {
     PCIDevice *d = (PCIDevice *)dev;
-    char path[50], name[33];
-    int off;
+    char name[33];
+    int has_func = !!PCI_FUNC(d->devfn);
 
-    off = snprintf(path, sizeof(path), "%s@%x",
-                   pci_dev_fw_name(dev, name, sizeof name),
-                   PCI_SLOT(d->devfn));
-    if (PCI_FUNC(d->devfn))
-        snprintf(path + off, sizeof(path) + off, ",%x", PCI_FUNC(d->devfn));
-    return g_strdup(path);
+    return g_strdup_printf("%s@%x%s%.*x",
+                           pci_dev_fw_name(dev, name, sizeof(name)),
+                           PCI_SLOT(d->devfn),
+                           has_func ? "," : "",
+                           has_func,
+                           PCI_FUNC(d->devfn));
 }
 
 static char *pcibus_get_dev_path(DeviceState *dev)