--- a/libstdc++-v3/configure	2011-02-15 19:21:13.116765002 -0600
+++ b/libstdc++-v3/configure	2011-02-15 19:38:24.217766630 -0600
@@ -44576,7 +44576,7 @@
 	;;
     esac
     ;;
-  *-linux* | *-uclinux* | *-gnu* | *-kfreebsd*-gnu | *-knetbsd*-gnu)
+  *-linux* | *-uclinux* | *-gnu* | *-kfreebsd*-gnu | *-knetbsd*-gnu | *-cygwin*)
 
   # All these tests are for C++; save the language and the compiler flags.
   # The CXXFLAGS thing is suspicious, but based on similar bits previously
--- a/libstdc++-v3/crossconfig.m4	2011-02-15 19:21:04.613764980 -0600
+++ b/libstdc++-v3/crossconfig.m4	2011-02-15 19:37:43.586763549 -0600
@@ -141,7 +141,7 @@
 	;;
     esac
     ;;
-  *-linux* | *-uclinux* | *-gnu* | *-kfreebsd*-gnu | *-knetbsd*-gnu)
+  *-linux* | *-uclinux* | *-gnu* | *-kfreebsd*-gnu | *-knetbsd*-gnu | *-cygwin*)
     GLIBCXX_CHECK_COMPILER_FEATURES
     GLIBCXX_CHECK_LINKER_FEATURES
     GLIBCXX_CHECK_MATH_SUPPORT