diff --git a/sys/msdos/video.c b/sys/msdos/video.c
index 3a883e428..62a5f990c 100644
--- a/sys/msdos/video.c
+++ b/sys/msdos/video.c
@@ -377,6 +377,21 @@ term_start_bgcolor(int bgcolor)
     // pline("after  bgcolor = %d, curframecolor = %d", bgcolor, curframecolor);
 }
 
+void
+term_start_extracolor(uint32 nhcolor UNUSED)
+{
+}
+
+void
+term_start_256color(int idx UNUSED)
+{
+}
+
+void
+term_end_extracolor(void)
+{
+}
+
 void
 term_start_raw_bold(void)
 {