diff --git a/doc/build_draft.sh b/doc/build_draft.sh
index 292571bea9db893de588a657a166902b59d101bb..d474819c1537d973bd3f9ba9784e26f38ca8fe2f 100755
--- a/doc/build_draft.sh
+++ b/doc/build_draft.sh
@@ -23,6 +23,8 @@ for f in `cat "${toplevel}"/opus_sources.mk "${toplevel}"/celt_sources.mk \
   cp -a "${toplevel}/${f}" "${destdir}/${f}"
 done
 cp -a "${toplevel}"/src/test_opus.c "${destdir}"/src/
+cp -a "${toplevel}"/src/test_opus_custom.c "${destdir}"/src/
+cp -a "${toplevel}"/src/opus_custom.h "${destdir}"/src/
 cp -a "${toplevel}"/Makefile.draft "${destdir}"/Makefile
 cp -a "${toplevel}"/opus_sources.mk "${destdir}"/
 cp -a "${toplevel}"/celt_sources.mk "${destdir}"/