diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index b27011cee7..c62c02f7b6 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -3081,7 +3081,7 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
     struct stat st;
     int i, ret;
     bool is_mdev;
-    char uuid[UUID_FMT_LEN];
+    char uuid[UUID_STR_LEN];
     char *name;
 
     if (!vbasedev->sysfsdev) {