diff --git a/term/sys/darwin/print.c b/term/sys/darwin/print.c
index dc2a629..21bd630 100644
--- a/term/sys/darwin/print.c
+++ b/term/sys/darwin/print.c
@@ -142,6 +142,7 @@ int z__b_stream_set_modifier(FILE *fp, enum z__b_stream_modifier mod)
 		nr_codes++;
 		break;
 	case Z__B_STREAM_MOD_BLUE:
+		buf[buf_i++] = '4';
 		nr_codes++;
 		break;
 	case Z__B_STREAM_MOD_RED | Z__B_STREAM_MOD_GREEN:
@@ -191,6 +192,7 @@ int z__b_stream_set_modifier(FILE *fp, enum z__b_stream_modifier mod)
 		nr_codes++;
 		break;
 	case Z__B_STREAM_MOD_BG_BLUE:
+		buf[buf_i++] = '4';
 		nr_codes++;
 		break;
 	case Z__B_STREAM_MOD_BG_RED | Z__B_STREAM_MOD_BG_GREEN: