diff -rupN src_orig/VBox/HostDrivers/VBoxNetAdp/linux/Makefile src/VBox/HostDrivers/VBoxNetAdp/linux/Makefile
--- src_orig/VBox/HostDrivers/VBoxNetAdp/linux/Makefile	2019-03-11 11:47:24.053811535 +0800
+++ src/VBox/HostDrivers/VBoxNetAdp/linux/Makefile	2019-03-11 11:50:09.534104474 +0800
@@ -58,7 +59,7 @@ VBOXMOD_DEFS = \
 	RT_WITH_VBOX \
 	VBOX_WITH_HARDENING \
 	VBOX_WITH_64_BITS_GUESTS # <-- must be consistent with Config.kmk!
-VBOXMOD_CFLAGS = -include $(KBUILD_EXTMOD)/include/VBox/SUPDrvMangling.h -fno-pie -Wno-declaration-after-statement
+VBOXMOD_CFLAGS = -include $(KBUILD_EXTMOD)/vboxnetadp/include/VBox/SUPDrvMangling.h -fno-pie -Wno-declaration-after-statement
 
 include $(obj)/Makefile-footer.gmk