--- m4/ax_pthread.m4.orig	2021-02-14 04:57:24.000000000 +1100
+++ m4/ax_pthread.m4	2022-02-10 10:57:24.177579000 +1100
@@ -152,7 +152,7 @@
 
 case $host_os in
 
-        freebsd*)
+        bsdsunix*|freebsd*)
 
         # -kthread: FreeBSD kernel threads (preferred to -pthread since SMP-able)
         # lthread: LinuxThreads port on FreeBSD (also preferred to -pthread)