diff --git a/slirp/sbuf.h b/slirp/sbuf.h
index a722ecb629..644c201341 100644
--- a/slirp/sbuf.h
+++ b/slirp/sbuf.h
@@ -8,7 +8,6 @@
 #ifndef SBUF_H
 #define SBUF_H
 
-#define sbflush(sb) sbdrop((sb),(sb)->sb_cc)
 #define sbspace(sb) ((sb)->sb_datalen - (sb)->sb_cc)
 
 struct sbuf {