diff --git a/drivers/pci/hotplug/pciehp_acpi.c b/drivers/pci/hotplug/pciehp_acpi.c
index 24d709b7388c..ead7c534095e 100644
--- a/drivers/pci/hotplug/pciehp_acpi.c
+++ b/drivers/pci/hotplug/pciehp_acpi.c
@@ -90,7 +90,7 @@ static int __init dummy_probe(struct pcie_device *dev)
 	slot = kzalloc(sizeof(*slot), GFP_KERNEL);
 	if (!slot)
 		return -ENOMEM;
-	slot->number = slot_cap >> 19;
+	slot->number = (slot_cap & PCI_EXP_SLTCAP_PSN) >> 19;
 	list_for_each_entry(tmp, &dummy_slots, list) {
 		if (tmp->number == slot->number)
 			dup_slot_id++;