diff --git a/ChangeLog b/ChangeLog
index 1cbd1eca8d..49444c3021 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Thu Jun  9 18:24:16 2005  Tanaka Akira  <akr@m17n.org>
+
+	* configure.in, eval.c, gc.c: use libunwind only on HP-UX.
+
 Wed Jun  8 12:25:59 2005  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* array.c (rb_ary_nitems): add the block feature to Array#nitems.
diff --git a/configure.in b/configure.in
index 4c51c0dfc8..00e4eb0f1d 100644
--- a/configure.in
+++ b/configure.in
@@ -492,7 +492,8 @@ AC_CHECK_FUNCS(fmod killpg wait4 waitpid fork spawnv syscall chroot fsync getcwd
 	      getpriority getrlimit setrlimit\
 	      dlopen sigprocmask sigaction _setjmp\
 	      setsid telldir seekdir fchmod mktime timegm cosh sinh tanh\
-	      setuid setgid daemon)
+	      setuid setgid daemon \
+	      _UNW_createContextForSelf)
 AC_ARG_ENABLE(setreuid,
        [  --enable-setreuid       use setreuid()/setregid() according to need even if obsolete.],
        [use_setreuid=$enableval])
@@ -597,7 +598,7 @@ AC_C_INLINE
 AC_C_VOLATILE
 
 if test x"$target_cpu" = xia64; then
-    if test x"$ac_cv_header_unwind_h" = xyes; then
+    if test x"$ac_cv_header_unwind_h" = xyes -a x"$ac_cv_func__UNW_createContextForSelf" = xyes; then
 	LIBS="-lunwind $LIBS"
     else
 	AC_CACHE_CHECK(IA64 backing store member in mcontext_t, rb_cv_ia64_bspstore,
diff --git a/eval.c b/eval.c
index 1bdb582017..348b2e27c2 100644
--- a/eval.c
+++ b/eval.c
@@ -9684,7 +9684,7 @@ Init_Binding()
  */
 #define __libc_ia64_register_backing_store_base (4ULL<<61)
 #else
-#ifdef HAVE_UNWIND_H
+#if defined(HAVE_UNWIND_H) && defined(HAVE__UNW_CREATECONTEXTFORSELF)
 #include <unwind.h>
 #else
 #pragma weak __libc_ia64_register_backing_store_base
@@ -10271,7 +10271,7 @@ rb_thread_save_context(th)
 #ifdef __ia64__
     {
 	VALUE *top, *bot;
-#ifdef HAVE_UNWIND_H
+#if defined(HAVE_UNWIND_H) && defined(HAVE__UNW_CREATECONTEXTFORSELF)
 	_Unwind_Context *unwctx = _UNW_createContextForSelf();
 
 	_UNW_currentContext(unwctx);
@@ -10431,7 +10431,7 @@ rb_thread_restore_context(th, exit)
 #ifdef __ia64__
     {
 	VALUE *base;
-#ifdef HAVE_UNWIND_H
+#if defined(HAVE_UNWIND_H) && defined(HAVE__UNW_CREATECONTEXTFORSELF)
 	_Unwind_Context *unwctx = _UNW_createContextForSelf();
 
 	_UNW_currentContext(unwctx);
diff --git a/gc.c b/gc.c
index 391412f806..c33be1616d 100644
--- a/gc.c
+++ b/gc.c
@@ -39,7 +39,7 @@
  */
 #define __libc_ia64_register_backing_store_base (4ULL<<61)
 #else
-#ifdef HAVE_UNWIND_H
+#if defined(HAVE_UNWIND_H) && defined(HAVE__UNW_CREATECONTEXTFORSELF)
 #include <unwind.h>
 #else
 #pragma weak __libc_ia64_register_backing_store_base
@@ -1347,14 +1347,14 @@ garbage_collect()
     {
 	ucontext_t ctx;
 	VALUE *top, *bot;
-#ifdef HAVE_UNWIND_H
+#if defined(HAVE_UNWIND_H) && defined(HAVE__UNW_CREATECONTEXTFORSELF)
 	_Unwind_Context *unwctx = _UNW_createContextForSelf();
 #endif
 
 	getcontext(&ctx);
 	mark_locations_array((VALUE*)&ctx.uc_mcontext,
 			     ((size_t)(sizeof(VALUE)-1 + sizeof ctx.uc_mcontext)/sizeof(VALUE)));
-#ifdef HAVE_UNWIND_H
+#if defined(HAVE_UNWIND_H) && defined(HAVE__UNW_CREATECONTEXTFORSELF)
 	_UNW_currentContext(unwctx);
 	bot = (VALUE*)(long)_UNW_getAR(unwctx, _UNW_AR_BSP);
 	top = (VALUE*)(long)_UNW_getAR(unwctx, _UNW_AR_BSPSTORE);