diff --git a/zh_TW.Big5/share/mk/doc.local.mk b/zh_TW.Big5/share/mk/doc.local.mk
new file mode 100644
index 0000000000..bc683bdae8
--- /dev/null
+++ b/zh_TW.Big5/share/mk/doc.local.mk
@@ -0,0 +1,5 @@
+# $FreeBSD$
+
+SP_ENCODING?=	${LANGCODE:C,^.*\.,,}
+
+SGMLFLAGS+= -D ${IMAGES_EN_DIR}/${DOC}s/${.CURDIR:T}