diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index c52b27d8b58..10f0aef9b0a 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -751,6 +751,7 @@ static void pci_setup_device(FAR struct pci_device_s *dev, int max_bar,
       start = res->start;
       res->start += size;
 #else
+      UNUSED(res);
       uint32_t tmp;
 
       pci_read_config_dword(dev, base_address_0, &tmp);