--- a/scanpci.c
+++ b/scanpci.c
@@ -11,8 +11,8 @@
 
 #define	die	printf
 
-struct pci_filter	filter;
-struct pci_access	*pacc;
+extern struct pci_filter	filter;
+extern struct pci_access	*pacc;
 static int		show_hex = 0;
 
 static struct device	*scan_device( struct pci_dev *p )