diff --git a/tools/test/travis-ci/doxy-spellchecker/ignore.en.pws b/tools/test/travis-ci/doxy-spellchecker/ignore.en.pws
index bda5d742a4..29f2d08361 100644
--- a/tools/test/travis-ci/doxy-spellchecker/ignore.en.pws
+++ b/tools/test/travis-ci/doxy-spellchecker/ignore.en.pws
@@ -114,4 +114,6 @@ api
 uart
 chrono
 Hinnant
+Vin
+Vref
 _doxy_