diff --git a/include/linux/pci.h b/include/linux/pci.h
index 0f76d0f..60ab8d7 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -170,6 +170,8 @@
 	PCI_DEV_FLAGS_NO_D3 = (__force pci_dev_flags_t) 2,
 	/* Provide indication device is assigned by a Virtual Machine Manager */
 	PCI_DEV_FLAGS_ASSIGNED = (__force pci_dev_flags_t) 4,
+	/* Flag for quirk use to store if quirk-specific ACS is enabled */
+	PCI_DEV_FLAGS_ACS_ENABLED_QUIRK = (__force pci_dev_flags_t) 8,
 };
 
 enum pci_irq_reroute_variant {