diff --git a/hw/xfree86/common/xf86Bus.c b/hw/xfree86/common/xf86Bus.c index 6c5c730a1..725a04b1a 100644 --- a/hw/xfree86/common/xf86Bus.c +++ b/hw/xfree86/common/xf86Bus.c @@ -266,7 +266,7 @@ StringToBusType(const char *busID, const char **retID) BusType ret = BUS_NONE; /* If no type field, Default to PCI */ - if (isdigit(busID[0])) { + if (isdigit((unsigned char)busID[0])) { if (retID) *retID = busID; return BUS_PCI;