--- src/build-data/cc/clang.txt.orig	2016-10-04 02:02:22 UTC
+++ src/build-data/cc/clang.txt
@@ -49,6 +49,7 @@ ppc64   -> "-m64"
 # This should probably be used on most/all targets, but the docs are incomplete
 openbsd -> "-pthread"
 freebsd -> "-pthread"
+bsdsunix  -> "-pthread"
 dragonfly -> "-pthread"
 netbsd  -> "-pthread -D_NETBSD_SOURCE"
 qnx     -> "-fexceptions -D_QNX_SOURCE"