diff --git a/arch/x86/kernel/pci-calgary_64.c b/arch/x86/kernel/pci-calgary_64.c
index e1e731d78f3821bb6f27950eca4033e52a77c606..d28bbdc35e4e5dec064bd1f9e5e7fbc548deaf4e 100644
--- a/arch/x86/kernel/pci-calgary_64.c
+++ b/arch/x86/kernel/pci-calgary_64.c
@@ -1567,7 +1567,7 @@ static int __init calgary_parse_options(char *p)
 				++p;
 			if (*p == '\0')
 				break;
-			bridge = simple_strtol(p, &endp, 0);
+			bridge = simple_strtoul(p, &endp, 0);
 			if (p == endp)
 				break;