diff --git a/ChangeLog b/ChangeLog
index abcf956ac7..df106b9aae 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Mon Feb 14 18:41:47 2011  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
+
+	* win32/setup.mak (USE_RUBYGEMS): fixed r30835. It didn't work on
+	  mswin32 port. If you changed win32/configure.bat, you should change
+	  setup.mak too.
+
 Mon Feb 14 17:28:34 2011  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
 
 	* test/ruby/test_system.rb (TestSystem#test_system_at):
diff --git a/win32/setup.mak b/win32/setup.mak
index 69444d019b..0733e99bbb 100644
--- a/win32/setup.mak
+++ b/win32/setup.mak
@@ -58,6 +58,10 @@ BASERUBY = $(BASERUBY:/=\)
 !if defined(NTVER)
 NTVER = $(NTVER)
 !endif
+!if defined(USE_RUBYGEMS)
+USE_RUBYGEMS = $(USE_RUBYGEMS)
+!endif
+
 <<
 !if !defined(BASERUBY)
 	@for %I in (ruby.exe) do @echo BASERUBY = %~s$$PATH:I>> $(MAKEFILE)