===================================================================
RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/tmux/format.c,v
retrieving revision 1.279
retrieving revision 1.280
diff -u -r1.279 -r1.280
--- src/usr.bin/tmux/format.c	2021/02/26 21:53:41	1.279
+++ src/usr.bin/tmux/format.c	2021/02/27 06:28:16	1.280
@@ -1,4 +1,4 @@
-/* $OpenBSD: format.c,v 1.279 2021/02/26 21:53:41 nicm Exp $ */
+/* $OpenBSD: format.c,v 1.280 2021/02/27 06:28:16 nicm Exp $ */
 
 /*
  * Copyright (c) 2011 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -1368,8 +1368,11 @@
 static void *
 format_cb_client_termtype(struct format_tree *ft)
 {
-	if (ft->c != NULL)
+	if (ft->c != NULL) {
+		if (ft->c->term_type == NULL)
+			return (xstrdup(""));
 		return (xstrdup(ft->c->term_type));
+	}
 	return (NULL);
 }