diff --git a/src/hb-ot-shape-complex-indic-private.hh b/src/hb-ot-shape-complex-indic-private.hh
index d44e82b1c..c3c51fed8 100644
--- a/src/hb-ot-shape-complex-indic-private.hh
+++ b/src/hb-ot-shape-complex-indic-private.hh
@@ -111,7 +111,7 @@ enum indic_syllabic_category_t {
   INDIC_SYLLABIC_CATEGORY_NUKTA			= OT_N,
   INDIC_SYLLABIC_CATEGORY_REGISTER_SHIFTER	= OT_RS,
   INDIC_SYLLABIC_CATEGORY_TONE_LETTER		= OT_X,
-  INDIC_SYLLABIC_CATEGORY_TONE_MARK		= OT_X,
+  INDIC_SYLLABIC_CATEGORY_TONE_MARK		= OT_N,
   INDIC_SYLLABIC_CATEGORY_VIRAMA		= OT_H,
   INDIC_SYLLABIC_CATEGORY_VISARGA		= OT_SM,
   INDIC_SYLLABIC_CATEGORY_VOWEL			= OT_V,