diff -Naur flex-2.5.37/config.guess flex-2.5.37-msys/config.guess
--- flex-2.5.37/config.guess	2012-07-23 04:31:59 +0400
+++ flex-2.5.37-msys/config.guess	2013-02-24 15:55:38 +0400
@@ -797,6 +797,9 @@
     i*:CYGWIN*:*)
 	echo ${UNAME_MACHINE}-pc-cygwin
 	exit ;;
+    i*:MSYS*:*)
+	echo ${UNAME_MACHINE}-pc-msys
+	exit ;;
     *:MINGW*:*)
 	echo ${UNAME_MACHINE}-pc-mingw32
 	exit ;;
@@ -837,6 +840,9 @@
     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 ;;
diff -Naur flex-2.5.37/config.rpath flex-2.5.37-msys/config.rpath
--- flex-2.5.37/config.rpath	2012-07-23 04:31:52 +0400
+++ flex-2.5.37-msys/config.rpath	2013-02-24 15:55:09 +0400
@@ -109,7 +109,7 @@
 hardcode_minus_L=no
 
 case "$host_os" in
-  cygwin* | mingw* | pw32*)
+  cygwin* | msys* | mingw* | pw32*)
     # FIXME: the MSVC++ port hasn't been tested in a loooong time
     # When not using gcc, we currently assume that we are using
     # Microsoft Visual C++.
@@ -149,7 +149,7 @@
         ld_shlibs=no
       fi
       ;;
-    cygwin* | mingw* | pw32*)
+    cygwin* | msys* | mingw* | pw32*)
       # hardcode_libdir_flag_spec is actually meaningless, as there is
       # no search path for DLLs.
       hardcode_libdir_flag_spec='-L$libdir'
@@ -268,7 +268,7 @@
       ;;
     bsdi4*)
       ;;
-    cygwin* | mingw* | pw32*)
+    cygwin* | msys* | mingw* | pw32*)
       # When not using gcc, we currently assume that we are using
       # Microsoft Visual C++.
       # hardcode_libdir_flag_spec is actually meaningless, as there is
@@ -440,7 +440,7 @@
     ;;
   bsdi4*)
     ;;
-  cygwin* | mingw* | pw32*)
+  cygwin* | msys* | mingw* | pw32*)
     shrext=.dll
     ;;
   darwin* | rhapsody*)
diff -Naur flex-2.5.37/config.sub flex-2.5.37-msys/config.sub
--- flex-2.5.37/config.sub	2012-07-23 04:31:59 +0400
+++ flex-2.5.37-msys/config.sub	2013-02-24 15:54:45 +0400
@@ -1281,7 +1281,7 @@
 	      | -ptx* | -coff* | -ecoff* | -winnt* | -domain* | -vsta* \
 	      | -udi* | -eabi* | -lites* | -ieee* | -go32* | -aux* \
 	      | -chorusos* | -chorusrdb* | -cegcc* \
-	      | -cygwin* | -pe* | -psos* | -moss* | -proelf* | -rtems* \
+	      | -cygwin* | -msys* | -pe* | -psos* | -moss* | -proelf* | -rtems* \
 	      | -mingw32* | -linux-gnu* | -linux-newlib* | -linux-uclibc* \
 	      | -uxpv* | -beos* | -mpeix* | -udk* \
 	      | -interix* | -uwin* | -mks* | -rhapsody* | -darwin* | -opened* \