diff --git a/ChangeLog b/ChangeLog
index ffee964109..e596647dd6 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Fri Jan 28 11:53:19 2011  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
+
+	* configure.in: redundant variable names made strange conftest
+	  error. Fixed it.
+
 Fri Jan 28 11:47:00 2011  NAKAMURA Usaku  <usa@ruby-lang.org>
 
 	* test/ruby/test_process.rb (TestProcess#test_too_long_path{,2}):
diff --git a/configure.in b/configure.in
index 4ef9e37a5c..8e1bc3b6e4 100644
--- a/configure.in
+++ b/configure.in
@@ -659,9 +659,9 @@ AC_DEFUN([RUBY_REPLACE_TYPE], [dnl
 			[typedef $n rbcv_conftest_target_type;
 			typedef $t rbcv_conftest_replace_type;
 			extern rbcv_conftest_target_type rbcv_conftest_var;
-			extern rbcv_conftest_replace_type rbcv_conftest_var;
+			extern rbcv_conftest_replace_type rbcv_conftest_var2;
 			extern rbcv_conftest_target_type rbcv_conftest_func(void);
-			extern rbcv_conftest_replace_type rbcv_conftest_func(void);
+			extern rbcv_conftest_replace_type rbcv_conftest_func2(void);
 			], [sizeof(rbcv_conftest_target_type) == sizeof(rbcv_conftest_replace_type)])],
 		    [n="$t"; break])
 	    done