diff --git a/sys/conf/kern.mk b/sys/conf/kern.mk
--- a/sys/conf/kern.mk
+++ b/sys/conf/kern.mk
@@ -331,3 +331,11 @@
 LD_EMULATION_powerpc64le= elf64lppc_fbsd
 LD_EMULATION_riscv64= elf64lriscv
 LD_EMULATION=${LD_EMULATION_${MACHINE_ARCH}}
+
+#
+# Autogenerated files must be located in the current object directory
+# and not the one belonging to the parent build. This prevents kernel
+# modules from using autogenerated files from the kernel build.
+# This is only an issue when <bsd.subdir.mk> is used.
+#
+.NOPATH: ${CLEAN} ${CLEANFILES}