diff --git a/src/encoder.c b/src/encoder.c
index d44fa12d..ff07cb6b 100644
--- a/src/encoder.c
+++ b/src/encoder.c
@@ -828,7 +828,8 @@ void encode_sao_color(encoder_control *encoder, sao_info *sao, color_index color
   cabac.ctx = &g_sao_type_idx_model;
   if (color_i == COLOR_Y) {
     CABAC_BIN(&cabac, sao->type, "sao_type_idx_luma");
-  } else {
+  } else if (color_i == COLOR_U) {
+    // SAO type is only coded for the first chroma.
     CABAC_BIN(&cabac, sao->type, "sao_type_idx_chroma");
   }