diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 22bb4198dc7..a2054ecbf0f 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,7 @@
+2007-12-28  YAMAMOTO Mitsuharu  <mituharu@math.s.chiba-u.ac.jp>
+
+	* progmodes/grep.el (rgrep): Fix last change.
+
 2007-12-27  Richard Stallman  <rms@gnu.org>
 
 	* progmodes/compile.el (compilation-start): Set initial visible
diff --git a/lisp/progmodes/grep.el b/lisp/progmodes/grep.el
index ecc386404c6..433c2705cd5 100644
--- a/lisp/progmodes/grep.el
+++ b/lisp/progmodes/grep.el
@@ -753,7 +753,7 @@ This command shares argument histories with \\[lgrep] and \\[grep-find]."
 			      " " find-name-arg " "
 			      (mapconcat #'shell-quote-argument
 					 (split-string files)
-					 " -o " find-name-arg " ")
+					 (concat " -o " find-name-arg " "))
 			      " "
 			      (shell-quote-argument ")"))
 		       dir