===================================================================
RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/mandoc/html.c,v
retrieving revision 1.149
retrieving revision 1.150
diff -u -r1.149 -r1.150
--- src/usr.bin/mandoc/html.c	2022/07/06 14:27:55	1.149
+++ src/usr.bin/mandoc/html.c	2022/08/09 11:21:50	1.150
@@ -1,4 +1,4 @@
-/* $OpenBSD: html.c,v 1.149 2022/07/06 14:27:55 schwarze Exp $ */
+/* $OpenBSD: html.c,v 1.150 2022/08/09 11:21:50 schwarze Exp $ */
 /*
  * Copyright (c) 2008-2011, 2014 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2011-2015, 2017-2021 Ingo Schwarze <schwarze@openbsd.org>
@@ -401,10 +401,13 @@
 	 * In addition, reserve '~' for ordinal suffixes.
 	 */
 
-	for (cp = buf; *cp != '\0'; cp++)
-		if (isalnum((unsigned char)*cp) == 0 &&
+	for (cp = buf; *cp != '\0'; cp++) {
+		if (*cp == ASCII_HYPH)
+			*cp = '-';
+		else if (isalnum((unsigned char)*cp) == 0 &&
 		    strchr("!$&'()*+,-./:;=?@_", *cp) == NULL)
 			*cp = '_';
+	}
 
 	if (unique == 0)
 		return buf;