--- m4/pthread_sigmask.m4.orig	2020-06-03 23:04:44.000000000 +1000
+++ m4/pthread_sigmask.m4	2020-07-31 00:09:05.475419000 +1000
@@ -138,7 +138,7 @@
                 [
                  changequote(,)dnl
                  case "$host_os" in
-                   freebsd* | hpux* | solaris | solaris2.[2-9]*)
+                   bsdsunix* | freebsd* | hpux* | solaris | solaris2.[2-9]*)
                      gl_cv_func_pthread_sigmask_in_libc_works="guessing no";;
                    *)
                      gl_cv_func_pthread_sigmask_in_libc_works="guessing yes";;