diff --git a/ChangeLog b/ChangeLog
index 73e8f1d32b..efc41ca39e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Mon Feb 27 10:54:20 2012  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* lib/mkmf.rb (try_cppflags, try_cflags, try_ldflags): replace the
+	  target flags if the given flag is accepted.
+
 Mon Feb 27 10:53:44 2012  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* test/rubygems/test_gem_specification.rb (test_self_from_yaml_syck_default_key_bug):
diff --git a/lib/mkmf.rb b/lib/mkmf.rb
index a29e5bafbd..9f31166b5f 100644
--- a/lib/mkmf.rb
+++ b/lib/mkmf.rb
@@ -550,6 +550,12 @@ MSG
     $CPPFLAGS = cppflags unless ret
   end
 
+  def try_cppflags(flags)
+    with_cppflags(flags) do
+      try_header("int main() {return 0;}")
+    end
+  end
+
   def with_cflags(flags)
     cflags = $CFLAGS
     $CFLAGS = flags
@@ -558,6 +564,12 @@ MSG
     $CFLAGS = cflags unless ret
   end
 
+  def try_cflags(flags)
+    with_cflags(flags) do
+      try_compile("int main() {return 0;}")
+    end
+  end
+
   def with_ldflags(flags)
     ldflags = $LDFLAGS
     $LDFLAGS = flags
@@ -566,6 +578,12 @@ MSG
     $LDFLAGS = ldflags unless ret
   end
 
+  def try_ldflags(flags)
+    with_ldflags(flags) do
+      try_link("int main() {return 0;}")
+    end
+  end
+
   def try_static_assert(expr, headers = nil, opt = "", &b)
     headers = cpp_include(headers)
     try_compile(<<SRC, opt, &b)