--- configure.orig	2016-04-18 22:06:13 UTC
+++ configure
@@ -6073,7 +6073,7 @@ $as_echo "$as_me: WARNING: we do not kno
 $as_echo_n "checking if more special flags are required for pthreads... " >&6; }
         flag=no
         case "${host_cpu}-${host_os}" in
-                *-aix* | *-freebsd*)     flag="-D_THREAD_SAFE";;
+                *-aix* | *-freebsd* | *-bsdsunix*)     flag="-D_THREAD_SAFE";;
                 *solaris* | *-osf* | *-hpux*) flag="-D_REENTRANT";;
         esac
         { $as_echo "$as_me:${as_lineno-$LINENO}: result: ${flag}" >&5