diff --git a/ChangeLog b/ChangeLog
index 8dedb7e157..26e8760f43 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sat Oct  3 01:01:03 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* configure.in: workaround for regexp metacharacters of expr in
+	  prefix path.
+
 Sat Oct  3 00:47:52 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* test/ripper/dummyparser.rb (DummyParser): improvement by Magnus
diff --git a/configure.in b/configure.in
index e56766244c..151970d22b 100644
--- a/configure.in
+++ b/configure.in
@@ -2450,7 +2450,7 @@ else
     RUBY_VENDOR_LIB_PATH="`eval echo \\"$VENDOR_DIR\\" | sed 's|^NONE/|'"$prefix"'/|'`"
 fi
 
-pat="$RUBY_LIB_PREFIX/"'\(.*\)'
+pat=`echo "$RUBY_LIB_PREFIX/" | tr -c '\012' .`'\(.*\)'
 RUBY_LIB_PATH='RUBY_LIB_PREFIX"/"RUBY_LIB_VERSION'
 case "$RUBY_SITE_LIB_PATH" in
   when("$RUBY_LIB_PREFIX/"*)