diff --git a/compat/toolkit/drivers/pci/pci.h b/compat/toolkit/drivers/pci/pci.h
new file mode 100644
index 0000000..cd87ed4
--- /dev/null
+++ b/compat/toolkit/drivers/pci/pci.h
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef REDPILL_PCI_H
+#define REDPILL_PCI_H
+
+#warning "Using compatibility file for drivers/pci/pci.h - if possible do NOT compile using toolkit"
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,18,0) && LINUX_VERSION_CODE < KERNEL_VERSION(4,20,0) //v4.18 - v4.20
+/* pci_dev priv_flags */
+#define PCI_DEV_ADDED 1
+
+static inline bool pci_dev_is_added(const struct pci_dev *dev)
+{
+	return test_bit(PCI_DEV_ADDED, &dev->priv_flags);
+}
+
+#elif LINUX_VERSION_CODE >= KERNEL_VERSION(4,20,0) && LINUX_VERSION_CODE < KERNEL_VERSION(6,0,0) //v4.20 - v6.0
+#define PCI_DEV_ADDED 0
+
+static inline bool pci_dev_is_added(const struct pci_dev *dev)
+{
+	return test_bit(PCI_DEV_ADDED, &dev->priv_flags);
+}
+#else
+static inline bool pci_dev_is_added(const struct pci_dev *dev)
+{
+	return 1 == dev->is_added;
+}
+#endif //LINUX_VERSION_CODE check
+
+#endif /* REDPILL_PCI_H */
diff --git a/internal/uart/uart_swapper.c b/internal/uart/uart_swapper.c
index 28e4991..8e5a745 100644
--- a/internal/uart/uart_swapper.c
+++ b/internal/uart/uart_swapper.c
@@ -373,7 +373,7 @@ static inline void restart_port(struct uart_8250_port *up)
     // because we did swap IRQ values. However, we MUST restart such port not to reinit the hardware (which doesn't
     // care) but to fix the interrupt mapping in the kernel!
     //skip extensive tests - it was working before
-#if LINUX_VERSION_CODE <= KERNEL_VERSION(5,0,0)
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4,14,0)
     port->flags |= UPF_NO_TXEN_TEST;
 #else
     port->quirks |= UPQ_NO_TXEN_TEST;
diff --git a/internal/virtual_pci.c b/internal/virtual_pci.c
index 6b7905c..72dd99f 100644
--- a/internal/virtual_pci.c
+++ b/internal/virtual_pci.c
@@ -176,6 +176,9 @@
 #include <linux/pci_ids.h> //Constants for vendors, classes, and other
 #include <linux/list.h> //list_for_each
 #include <linux/device.h> //device_del
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,18,0)
+#include <../drivers/pci/pci.h> //pci_dev_is_added
+#endif
 
 #define PCIBUS_VIRTUAL_DOMAIN 0x0001 //normal PC buses are (always?) on domain 0, this is just a next one
 #define PCI_DEVICE_NOT_FOUND_VID_DID 0xFFFFFFFF //A special case to detect non-existing devices (per PCI spec)
@@ -545,10 +548,10 @@ int vpci_remove_all_devices_and_buses(void)
     for_each_bus_idx() {
         list_for_each_entry_safe(pci_dev, pci_dev_n, &buses[i]->devices, bus_list) {
             pr_loc_dbg("Detaching vDEV dev=%02x fn=%02x from bus=%02x [add=%d]", PCI_SLOT(pci_dev->devfn),
-#if LINUX_VERSION_CODE <= KERNEL_VERSION(5,0,0)
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4,18,0)
                        PCI_FUNC(pci_dev->devfn), buses[i]->number, pci_dev->is_added);
 #else
-                       PCI_FUNC(pci_dev->devfn), buses[i]->number, 0);  // Not found a replacement for pci_dev->is_added
+                       PCI_FUNC(pci_dev->devfn), buses[i]->number, pci_dev_is_added(pci_dev));
 #endif
             pci_stop_and_remove_bus_device(pci_dev);
         }
diff --git a/shim/bios_shim.c b/shim/bios_shim.c
index 55f7c34..48d7656 100644
--- a/shim/bios_shim.c
+++ b/shim/bios_shim.c
@@ -348,10 +348,12 @@ static int _apply_relocate_add(Elf64_Shdr *sechdrs, const char *strtab, unsigned
                 val -= (u64)loc;
                 *(u32 *)loc = val;
                 break;
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,20,0)
             case R_X86_64_PC64:
                 val -= (u64)loc;
                 *(u64 *)loc = val;
                 break;
+#endif
             default:
                 pr_err("%s: Unknown rela relocation: %llu\n",
                        me->name, ELF64_R_TYPE(rel[i].r_info));