--- configure.in.orig	2016-10-02 18:14:40.803581000 +0200
+++ configure.in	2016-10-02 18:13:54.845182000 +0200
@@ -804,12 +804,12 @@
 ])
 
 AS_CASE(["$target_os"],
-[freebsd*], [
+[bsdsunix*|freebsd*], [
   AC_CACHE_CHECK([whether pthread should be enabled by default],
     rb_cv_enable_pthread_default,
     [AC_TRY_CPP([
 #include <osreldate.h>
-#if __FreeBSD_version < 502102
+#if __FreeBSD_version < 502102 && !defined(__BSDSUniX__)
 #error pthread should be disabled on this platform
 #endif
       ],
@@ -953,7 +953,7 @@
 		AC_DEFINE(BROKEN_SETREUID, 1)
 		AC_DEFINE(BROKEN_SETREGID, 1)
                 ac_cv_sizeof_rlim_t=8],
-[freebsd*], [	LIBS="-lm $LIBS"
+[bsdsunix*|freebsd*], [	LIBS="-lm $LIBS"
 		ac_cv_func_getpeername=no
 		ac_cv_func_getsockname=no
 		ac_cv_func_shutdown=no
@@ -1644,7 +1644,7 @@
 	rb_cv_broken_glibc_ia64_erfc=no)])
 AS_CASE([$rb_cv_broken_glibc_ia64_erfc],[yes],[ac_cv_func_erf=no])
 
-AS_CASE(["$target_os"],[freebsd*],[
+AS_CASE(["$target_os"],[bsdsunix*|freebsd*],[
 	 AC_DEFINE(BROKEN_CLOSE)
 	 AC_REPLACE_FUNCS(close)
 	 ])
@@ -2365,7 +2365,7 @@
 			XLDFLAGS="$XLDFLAGS -Wl,-E"
 			LIBPATHFLAG=" -L%1\$-s"
 			rb_cv_dlopen=yes],
-	[freebsd*|dragonfly*], [
+	[bsdsunix*|freebsd*|dragonfly*], [
 			: ${LDSHARED='$(CC) -shared'}
 			if test "$rb_cv_binary_elf" = yes; then
 			    LDFLAGS="$LDFLAGS -rdynamic"
@@ -2486,7 +2486,7 @@
 	])
 
 AS_CASE(["$target_cpu-$target_os"],
-[*-freebsd*|x86_64-netbsd*], [
+[*-bsdsunix*|*-freebsd*|x86_64-netbsd*], [
     AC_CHECK_HEADERS([execinfo.h])
     if test "x$ac_cv_header_execinfo_h" = xyes; then
 	AC_CHECK_LIB([execinfo], [backtrace])
@@ -2730,7 +2730,7 @@
   AC_DEFINE_UNQUOTED(LIBDIR_BASENAME, ["${libdir_basename}"])
 
   AS_CASE(["$target_os"],
-    [freebsd*|dragonfly*], [],
+    [bsdsunix*|freebsd*|dragonfly*], [],
     [
      if test "$GCC" = yes; then
        RUBY_TRY_LDFLAGS([${linker_flag}--no-undefined], [no_undefined=yes], [no_undefined=no])
@@ -2752,7 +2752,7 @@
 	    LIBRUBY_RELATIVE=yes
 	fi
 	],
-    [freebsd*|dragonfly*], [
+    [bsdsunix*|freebsd*|dragonfly*], [
 	SOLIBS='$(LIBS)'
 	LIBRUBY_SO='lib$(RUBY_SO_NAME).so.$(MAJOR)$(MINOR)'
 	LIBRUBY_DLDFLAGS='-Wl,-soname,$(LIBRUBY_SO)'
@@ -2911,7 +2911,7 @@
             DTRACE_GLOMMED_OBJ='ruby-glommed.$(OBJEXT)'
             LIBRUBY_A_OBJS='$(DTRACE_GLOMMED_OBJ)'
         fi
-        AS_CASE("${target_os}", [freebsd*], [
+        AS_CASE("${target_os}", [bsdsunix*|freebsd*], [
             # FreeBSD's dtrace requires libelf
             LIBS="-lelf $LIBS"
         ])