diff --git a/pcidev.c b/pcidev.c
index f5ad819..54c1fd3 100644
--- a/pcidev.c
+++ b/pcidev.c
@@ -266,7 +266,7 @@
 	};
 };
 
-int undo_pci_write(void *p)
+static int undo_pci_write(void *p)
 {
 	struct undo_pci_write_data *data = p;
 	if (pacc == NULL || data->dev == NULL) {