diff --git a/ChangeLog b/ChangeLog
index 613f1dd7a0..a037e4ed1b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sat Sep 25 21:56:25 2010  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
+
+	* configure.in: Always add -mieee for Renesas SH4.
+	Thanks, Nobuhiro Iwamatsu. [Feature #3874] [ruby-core:32548]
+
 Sat Sep 25 01:17:39 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* ext/stringio/stringio.c (Init_stringio): added readpartial,
diff --git a/configure.in b/configure.in
index 56807251d9..4ff0cda630 100644
--- a/configure.in
+++ b/configure.in
@@ -586,12 +586,13 @@ AC_CHECK_LIB(dl, dlopen)	# Dynamic linking for SunOS/Solaris and SYSV
 AC_CHECK_LIB(dld, shl_load)	# Dynamic linking for HP-UX
 AC_CHECK_LIB(rt, clock_gettime)	# GNU/Linux
 
-case "$target_cpu" in
-alpha*)		case "$target_os"::"$GCC" in
-		*::yes)	CFLAGS="-mieee $CFLAGS" ;;   # gcc
-		osf*)   CFLAGS="-ieee $CFLAGS" ;;    # ccc
-		esac ;;
-esac
+AS_CASE(["$target_cpu"],
+[alpha*|sh4|sh4el|sh4eb], [AS_CASE(["$target_os"::"$GCC"],
+		[*::yes],  # gcc
+			[CFLAGS="-mieee $CFLAGS"],
+		[osf*],    # ccc
+			[CFLAGS="-ieee $CFLAGS"],
+		)])
 
 dnl Checks for header files.
 AC_HEADER_DIRENT