diff --git a/sys/conf/files.mips b/sys/conf/files.mips
index 2c3bd51..c301160 100644
--- a/sys/conf/files.mips
+++ b/sys/conf/files.mips
@@ -52,7 +52,8 @@ kern/kern_clocksource.c                       standard
 kern/link_elf_obj.c                    standard
 kern/subr_busdma_bufalloc.c            standard
 kern/subr_dummy_vdso_tc.c              standard
-kern/subr_sfbuf.c                      standard
+kern/subr_sfbuf.c                      optional        mips | mipsel | mipsn32
+kern/subr_sfbuf.c                      optional        mipshf | mipselhf | mipsn32hf
 
 # gcc/clang runtime
 libkern/ffsl.c                         standard