diff --git a/hw/xfree86/os-support/bus/xf86Pci.h b/hw/xfree86/os-support/bus/xf86Pci.h
index c27ccfde2..57c3eef63 100644
--- a/hw/xfree86/os-support/bus/xf86Pci.h
+++ b/hw/xfree86/os-support/bus/xf86Pci.h
@@ -329,7 +329,7 @@
 #define PCI_MAP_IS_MEM(b)	(!PCI_MAP_IS_IO(b))
 
 #define PCI_MAP_IS64BITMEM(b)	\
-	(((b) & PCI_MAP_MEMORY_TYPE_MASK) == PCI_MAP_MEMORY_TYPE_64BIT)
+	(((b) & PCI_MAP_MEMORY_TYPE) == PCI_MAP_MEMORY_TYPE_64BIT)
 
 #define PCIGETMEMORY(b)		((b) & PCI_MAP_MEMORY_ADDRESS_MASK)
 #define PCIGETMEMORY64HIGH(b)	(*((CARD32*)&(b) + 1))