diff --git a/ChangeLog b/ChangeLog
index a87737fe65..73a0e7cf4e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Fri Jul  8 11:39:12 2011  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* common.mk (sudo-precheck): true command is not standard on
+	  Windows.
+
 Fri Jul  8 10:39:52 2011  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
 
 	* thread_pthread.c (gvl_destroy): fix cond_t leak.
diff --git a/Makefile.in b/Makefile.in
index a01faae931..531743d0e8 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -3,6 +3,7 @@ NULLCMD = :
 RUNCMD = $(SHELL)
 CHDIR = @CHDIR@
 exec = exec
+NULL = /dev/null
 
 #### Start of system configuration section. ####
 
diff --git a/common.mk b/common.mk
index 20bc23befb..0a4da6ddd1 100644
--- a/common.mk
+++ b/common.mk
@@ -929,7 +929,7 @@ love: sudo-precheck up all test install test-all
 	@echo love is all you need
 
 sudo-precheck:
-	@$(SUDO) true
+	@$(SUDO) echo > $(NULL)
 
 help: PHONY
 	$(MESSAGE_BEGIN) \