diff --git a/ChangeLog b/ChangeLog
index a03adcba92..42943a3332 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+Tue Jan 27 11:09:45 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* lib/mkmf.rb (try_header): checks the header depending on
+	  platform.
+
+	* lib/mkmf.rb (have_header, find_header): use try_header.
+
+	* win32/Makefile.sub (try_header): uses try_compile to get rid of
+	  slow -E option of VC.
+
 Tue Jan 27 11:03:52 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* common.mk (distclean-enc, realclean-enc): do not call clean of
diff --git a/lib/mkmf.rb b/lib/mkmf.rb
index 54db11829f..2cbbb245a9 100644
--- a/lib/mkmf.rb
+++ b/lib/mkmf.rb
@@ -433,6 +433,10 @@ ensure
   rm_f "conftest*"
 end
 
+class Object
+  alias_method :try_header, (config_string('try_header') || :try_cpp)
+end
+
 def cpp_include(header)
   if header
     header = [header] unless header.kind_of? Array
@@ -806,7 +810,7 @@ end
 #
 def have_header(header, &b)
   checking_for header do
-    if try_cpp(cpp_include(header), &b)
+    if try_header(cpp_include(header), &b)
       $defs.push(format("-DHAVE_%s", header.tr("a-z./\055", "A-Z___")))
       true
     else
@@ -825,13 +829,13 @@ def find_header(header, *paths)
   message = checking_message(header, paths)
   header = cpp_include(header)
   checking_for message do
-    if try_cpp(header)
+    if try_header(header)
       true
     else
       found = false
       paths.each do |dir|
         opt = "-I#{dir}".quote
-        if try_cpp(header, opt)
+        if try_header(header, opt)
           $INCFLAGS << " " << opt
           found = true
           break
diff --git a/win32/Makefile.sub b/win32/Makefile.sub
index ce3bbff0d2..f20009726f 100644
--- a/win32/Makefile.sub
+++ b/win32/Makefile.sub
@@ -654,6 +654,7 @@ s,@configure_args@,--with-make-prog=nmake --enable-shared $(configure_args),;t t
 s,@configure_input@,$$configure_input,;t t
 s,@srcdir@,$(srcdir),;t t
 s,@top_srcdir@,$(srcdir),;t t
+s,@try_header@,try_compile,;t t
 <<KEEP
 
 miniruby: miniruby$(EXEEXT)