diff --git a/configure b/configure
index ce6e2c7..b77d2bf 100755
--- a/configure
+++ b/configure
@@ -1,6 +1,8 @@
 #!/bin/sh
 #
 # Copyright (c) 2021 Omar Polo <op@omarpolo.com>
+# Copyright (c) 2011, 2013-2022 Ingo Schwarze <schwarze@openbsd.org>
+# Copyright (c) 2010, 2011, 2012 Kristaps Dzonsons <kristaps@bsd.lv>
 #
 # Permission to use, copy, modify, and distribute this software for any
 # purpose with or without fee is hereby granted, provided that the above
@@ -14,9 +16,6 @@
 # ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 # OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 
-# adapted from mandoc configure and oconfigure, thanks schwarze@ and
-# kristaps@!
-
 set -e
 
 [ -w config.log ] && mv config.log config.log.old