diff --git a/reactos/drivers/bus/pci/pdo.c b/reactos/drivers/bus/pci/pdo.c
index 7448fd276c4..bedaac36fc0 100644
--- a/reactos/drivers/bus/pci/pdo.c
+++ b/reactos/drivers/bus/pci/pdo.c
@@ -355,7 +355,9 @@ PdoGetRangeLength(PPDO_DEVICE_EXTENSION DeviceExtension,
         return TRUE;
     }
 
-    *Base = OriginalValue.Bar & PCI_ADDRESS_MEMORY_ADDRESS_MASK_64;
+    *Base = ((OriginalValue.Bar & PCI_ADDRESS_IO_SPACE)
+             ? (OriginalValue.Bar & PCI_ADDRESS_IO_ADDRESS_MASK_64)
+             : (OriginalValue.Bar & PCI_ADDRESS_MEMORY_ADDRESS_MASK_64));
 
     *Length = ~((NewValue.Bar & PCI_ADDRESS_IO_SPACE)
                 ? (NewValue.Bar & PCI_ADDRESS_IO_ADDRESS_MASK_64)