diff --git a/winsup/utils/ChangeLog b/winsup/utils/ChangeLog
index 93a94dca5..b0278c587 100644
--- a/winsup/utils/ChangeLog
+++ b/winsup/utils/ChangeLog
@@ -1,3 +1,8 @@
+2010-10-30  Dmitry Potapov  <dpotapov@gmail.com>
+
+	* regtool.c (cmd_set): Write correct number of bytes for REG_MULTI_SZ
+	case.
+
 2010-09-06  Corinna Vinschen  <corinna@vinschen.de>
 
 	* cygpath.cc (RtlEqualUnicodePathPrefix): New helper function.
@@ -1370,7 +1375,7 @@
 
 2006-10-16  Corinna Vinschen  <corinna@vinschen.de>
 
-	* regtool.cc (KEY_WOW64_64KEY): Drop definition.  Instead define 
+	* regtool.cc (KEY_WOW64_64KEY): Drop definition.  Instead define
 	WINVER to 0x0502 before including windows.h.
 
 2006-10-16  Corinna Vinschen  <corinna@vinschen.de>
diff --git a/winsup/utils/regtool.cc b/winsup/utils/regtool.cc
index c51479d60..0da7ecad0 100644
--- a/winsup/utils/regtool.cc
+++ b/winsup/utils/regtool.cc
@@ -711,7 +711,7 @@ cmd_set ()
 	n += mbstowcs ((wchar_t *) data + n, argv[i], max_n - n) + 1;
       ((wchar_t *)data)[n] = L'\0';
       rv = RegSetValueExW (key, value, 0, REG_MULTI_SZ, (const BYTE *) data,
-			   (max_n + 1) * sizeof (wchar_t));
+			   (n + 1) * sizeof (wchar_t));
       break;
     case REG_AUTO:
       rv = ERROR_SUCCESS;