diff --git a/configure.ac b/configure.ac
index 0796b06943..2b25d7b069 100644
--- a/configure.ac
+++ b/configure.ac
@@ -950,26 +950,7 @@ AS_CASE(["$target_os"],
   RUBY_APPEND_OPTION(CPPFLAGS, -D__MINGW_USE_VC2005_COMPAT)
 ])
 
-AS_CASE(["$target_os"],
-[freebsd*], [
-  AC_CACHE_CHECK([whether pthread should be enabled by default],
-    rb_cv_enable_pthread_default,
-    [AC_PREPROC_IFELSE([AC_LANG_SOURCE([[
-#include <osreldate.h>
-#if __FreeBSD_version < 502102
-#error pthread should be disabled on this platform
-#endif
-      ]])],
-      rb_cv_enable_pthread_default=yes,
-      rb_cv_enable_pthread_default=no)])
-  enable_pthread=$rb_cv_enable_pthread_default
-  ],
-[mingw*], [
-  enable_pthread=no
-  ],
-[
-  enable_pthread=yes
-  ])
+RUBY_THREAD
 
 dnl Checks for libraries.
 AS_CASE(["$target_os"],[*bsd*|dragonfly*],[],[ac_cv_func_daemon=no])
@@ -2652,25 +2633,7 @@ AC_DEFINE_UNQUOTED(COROUTINE_H, ["$COROUTINE_H"])
 AC_SUBST(X_COROUTINE_H, [$COROUTINE_H])
 AC_SUBST(X_COROUTINE_SRC, [$COROUTINE_SRC])
 
-AS_IF([test x"$enable_pthread" = xyes], [
-    for pthread_lib in thr pthread pthreads c c_r root; do
-	AC_CHECK_LIB($pthread_lib, pthread_create,
-		     rb_with_pthread=yes, rb_with_pthread=no)
-	AS_IF([test "$rb_with_pthread" = "yes"], [break])
-    done
-    AS_IF([test x"$rb_with_pthread" = xyes], [
-	AC_DEFINE(_REENTRANT)
-	AC_DEFINE(_THREAD_SAFE)
-	AC_DEFINE(HAVE_LIBPTHREAD)
-	AC_CHECK_HEADERS(pthread_np.h, [], [], [@%:@include <pthread.h>])
-	AS_CASE(["$pthread_lib:$target_os"],
-		[c:*], [],
-		[root:*], [],
-		[c_r:*|*:openbsd*|*:mirbsd*],  [LIBS="-pthread $LIBS"],
-		[LIBS="-l$pthread_lib $LIBS"])
-    ], [
-	AC_MSG_WARN("Don't know how to find pthread library on your system -- thread support disabled")
-    ])
+AS_IF([test "$THREAD_MODEL" = pthread], [
     AC_CACHE_CHECK([whether pthread_t is scalar type], [rb_cv_scalar_pthread_t], [
 	AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
 	    @%:@include <pthread.h>
@@ -2759,12 +2722,12 @@ AS_IF([test x"$ac_cv_header_ucontext_h" = xyes -o x"$rb_cv_ucontext_in_signal_h"
     ], [
 	AC_DEFINE_UNQUOTED(DEFINE_MCONTEXT_PTR(mc, uc), mcontext_t *mc = &(uc)->uc_mcontext)
     ])
-    AS_IF([test x"$rb_with_pthread" = xyes], [
+    AS_IF([test x"$THREAD_MODEL" = xpthread], [
 	AC_CHECK_FUNCS(getcontext setcontext)
     ])
 ])
 
-AS_IF([test "$ac_cv_func_fork_works" = "yes" -a "$rb_with_pthread" = "yes"], [
+AS_IF([test "$ac_cv_func_fork_works" = "yes" -a x"$THREAD_MODEL" = xpthread], [
     AC_CACHE_CHECK([if fork works with pthread], rb_cv_fork_with_pthread,
 	[AC_RUN_IFELSE([AC_LANG_SOURCE([[
 #include <stdlib.h>
@@ -3893,8 +3856,6 @@ AS_CASE(["$target_os"],
 
 MINIOBJS="$MINIDLNOBJ"
 
-RUBY_THREAD
-
 AC_ARG_ENABLE(debug-env,
        AS_HELP_STRING([--enable-debug-env], [enable RUBY_DEBUG environment variable]),
        [AC_SUBST(ENABLE_DEBUG_ENV, yes)])
@@ -4421,7 +4382,7 @@ config_summary "site libraries path" "$rubysitearchprefix"
 config_summary "vendor path"         "$vendordir"
 config_summary "target OS"           "$target_os"
 config_summary "compiler"            "$CC"
-config_summary "with pthread"        "$enable_pthread"
+config_summary "with thread"         "$THREAD_MODEL"
 config_summary "with coroutine"      "$coroutine_type"
 config_summary "enable shared libs"  "$ENABLE_SHARED"
 config_summary "dynamic library ext" "$DLEXT"
diff --git a/tool/m4/ruby_thread.m4 b/tool/m4/ruby_thread.m4
index 2e58eddb98..439c63bc22 100644
--- a/tool/m4/ruby_thread.m4
+++ b/tool/m4/ruby_thread.m4
@@ -5,6 +5,21 @@ AC_ARG_WITH(thread,
     [THREAD_MODEL=$withval], [
     THREAD_MODEL=
     AS_CASE(["$target_os"],
+        [freebsd*], [
+            AC_CACHE_CHECK([whether pthread should be enabled by default],
+                rb_cv_enable_pthread_default,
+                [AC_PREPROC_IFELSE([AC_LANG_SOURCE([[
+@%:@include <osreldate.h>
+@%:@if __FreeBSD_version < 502102
+@%:@error pthread should be disabled on this platform
+@%:@endif
+                    ]])],
+                    rb_cv_enable_pthread_default=yes,
+                    rb_cv_enable_pthread_default=no)])
+            AS_IF([test $rb_cv_enable_pthread_default = yes],
+                [THREAD_MODEL=pthread],
+                [THREAD_MODEL=none])
+        ],
         [mingw*], [
             THREAD_MODEL=win32
         ],
@@ -12,19 +27,47 @@ AC_ARG_WITH(thread,
             THREAD_MODEL=none
         ],
         [
-            AS_IF([test "$rb_with_pthread" = "yes"], [
-                THREAD_MODEL=pthread
-            ])
+            THREAD_MODEL=pthread
         ]
     )
 ])
 
+AS_IF([test x"$THREAD_MODEL" = xpthread], [
+    AC_CHECK_HEADERS(pthread.h)
+    AS_IF([test x"$ac_cv_header_pthread_h" = xyes], [], [
+	AC_MSG_WARN("Don't know how to find pthread header on your system -- thread support disabled")
+        THREAD_MODEL=none
+    ])
+])
+AS_IF([test x"$THREAD_MODEL" = xpthread], [
+    THREAD_MODEL=none
+    for pthread_lib in thr pthread pthreads c c_r root; do
+	AC_CHECK_LIB($pthread_lib, pthread_create,
+		     [THREAD_MODEL=pthread; break])
+    done
+    AS_IF([test x"$THREAD_MODEL" = xpthread], [
+	AC_DEFINE(_REENTRANT)
+	AC_DEFINE(_THREAD_SAFE)
+	AC_DEFINE(HAVE_LIBPTHREAD)
+	AC_CHECK_HEADERS(pthread_np.h, [], [], [@%:@include <pthread.h>])
+	AS_CASE(["$pthread_lib:$target_os"],
+		[c:*], [],
+		[root:*], [],
+		[c_r:*|*:openbsd*|*:mirbsd*],  [LIBS="-pthread $LIBS"],
+		[LIBS="-l$pthread_lib $LIBS"])
+    ], [
+	AC_MSG_WARN("Don't know how to find pthread library on your system -- thread support disabled")
+    ])
+])
+
 AS_CASE(["$THREAD_MODEL"],
-[pthread], [AC_CHECK_HEADERS(pthread.h)],
+[pthread], [],
 [win32],   [],
 [none],    [],
 [""],      [AC_MSG_ERROR(thread model is missing)],
            [AC_MSG_ERROR(unknown thread model $THREAD_MODEL)])
+AC_MSG_CHECKING(thread model)
+AC_MSG_RESULT($THREAD_MODEL)
 
 THREAD_IMPL_H=thread_$THREAD_MODEL.h
 AS_IF([test ! -f "$srcdir/$THREAD_IMPL_H"],