diff --git a/ChangeLog b/ChangeLog
index 952630fa7a..4715c35edc 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sun Dec 30 06:27:38 2007  NAKAMURA Usaku  <usa@ruby-lang.org>
+
+	* lib/mkmf.rb (depend_rules): need to convert `/' to `\' for windows
+	  native commands.
+
 Sun Dec 30 01:43:56 2007  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* enc/Makefile.in (DLDFLAGS): like as extensions.  [ruby-core:14567]
diff --git a/lib/mkmf.rb b/lib/mkmf.rb
index 055ed226ea..d99209e2d6 100644
--- a/lib/mkmf.rb
+++ b/lib/mkmf.rb
@@ -1308,6 +1308,10 @@ def depend_rules(depend)
     line.gsub!(/\.o\b/, ".#{$OBJEXT}")
     line.gsub!(/\$\((?:hdr|top)dir\)\/config.h/, $config_h) if $config_h
     line.gsub!(%r"\$\(hdrdir\)/(?!ruby(?![^:;/\s]))(?=[-\w]+\.h)", '\&ruby/')
+    if $nmake && /\A\s*\$\(RM|COPY\)/ =~ line
+      line.gsub!(%r"[-\w\./]{2,}"){$&.tr("/", "\\")}
+      line.gsub!(/(\$\((?!RM|COPY)[^:)]+)(?=\))/, '\1:/=\\')
+    end
     if /(?:^|[^\\])(?:\\\\)*\\$/ =~ line
       (cont ||= []) << line
       next