--- Makefile.in.orig	2008-05-31 16:57:11.000000000 +0200
+++ Makefile.in	2008-10-04 11:36:10.000000000 +0200
@@ -134,7 +134,7 @@
 		if RUBY_PLATFORM =~ /mswin|bccwin|mingw/; \
 		  class File; \
 		    remove_const :ALT_SEPARATOR; \
-		    ALT_SEPARATOR = "\\"; \
+		    ALT_SEPARATOR = "\\\\"; \
 		  end; \
 		end; \
 		' > $@