diff -Naur diffstat-1.58/config.guess diffstat-1.58-msys/config.guess
--- diffstat-1.58/config.guess	2013-02-10 14:28:37.000000000 +0000
+++ diffstat-1.58-msys/config.guess	2013-04-10 11:28:19.249023400 +0000
@@ -845,6 +845,9 @@
     amd64:CYGWIN*:*:* | x86_64:CYGWIN*:*:*)
 	echo x86_64-unknown-cygwin
 	exit ;;
+    amd64:MSYS*:*:* | x86_64:MSYS*:*:*)
+	echo x86_64-unknown-msys
+	exit ;;
     p*:CYGWIN*:*)
 	echo powerpcle-unknown-cygwin
 	exit ;;