diff --git a/compat.c b/compat.c
index 0624dc6de..7c0e1c230 100644
--- a/compat.c
+++ b/compat.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: compat.c,v 1.113 2018/08/13 02:41:05 djm Exp $ */
+/* $OpenBSD: compat.c,v 1.114 2020/06/01 07:11:38 dtucker Exp $ */
 /*
  * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl.  All rights reserved.
  *
@@ -157,32 +157,6 @@ compat_datafellows(const char *version)
 	return 0;
 }
 
-#define	SEP	","
-int
-proto_spec(const char *spec)
-{
-	char *s, *p, *q;
-	int ret = SSH_PROTO_UNKNOWN;
-
-	if (spec == NULL)
-		return ret;
-	q = s = strdup(spec);
-	if (s == NULL)
-		return ret;
-	for ((p = strsep(&q, SEP)); p && *p != '\0'; (p = strsep(&q, SEP))) {
-		switch (atoi(p)) {
-		case 2:
-			ret |= SSH_PROTO_2;
-			break;
-		default:
-			logit("ignoring bad proto spec: '%s'.", p);
-			break;
-		}
-	}
-	free(s);
-	return ret;
-}
-
 char *
 compat_cipher_proposal(char *cipher_prop)
 {
diff --git a/compat.h b/compat.h
index d611d33e7..66db42cc0 100644
--- a/compat.h
+++ b/compat.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: compat.h,v 1.54 2018/08/13 02:41:05 djm Exp $ */
+/* $OpenBSD: compat.h,v 1.55 2020/06/01 07:11:38 dtucker Exp $ */
 
 /*
  * Copyright (c) 1999, 2000, 2001 Markus Friedl.  All rights reserved.
@@ -27,11 +27,6 @@
 #ifndef COMPAT_H
 #define COMPAT_H
 
-#define	SSH_PROTO_UNKNOWN	0x00
-#define	SSH_PROTO_1		0x01
-#define	SSH_PROTO_1_PREFERRED	0x02
-#define	SSH_PROTO_2		0x04
-
 #define SSH_BUG_UTF8TTYMODE	0x00000001
 #define SSH_BUG_SIGTYPE		0x00000002
 /* #define unused		0x00000004 */
@@ -64,7 +59,6 @@
 #define SSH_BUG_DHGEX_LARGE	0x40000000
 
 u_int    compat_datafellows(const char *);
-int	 proto_spec(const char *);
 char	*compat_cipher_proposal(char *);
 char	*compat_pkalg_proposal(char *);
 char	*compat_kex_proposal(char *);