diff --git a/m4/boinc_check_cygwin.m4 b/m4/boinc_check_cygwin.m4
new file mode 100644
index 0000000000..ff344092d0
--- /dev/null
+++ b/m4/boinc_check_cygwin.m4
@@ -0,0 +1,31 @@
+AC_DEFUN([BOINC_CHECK_CYGWIN],[
+  AC_MSG_CHECKING([whether we are compiling for cygwin])
+  case "$target" in 
+    *cygwin*)  
+        with_cygwin=yes
+	;;
+    *)  with_cygwin=no
+        ;;
+  esac
+  AC_MSG_RESULT($with_cygwin)
+  if test "${with_cygwin}" = "yes" ; then
+    AC_MSG_CHECKING([whether to use X11 or WIN32 GUI])
+    if test "${with_x+set}" = set; then
+       with_x="${with_x}"
+    else
+       with_x="no"
+    fi
+    if test "${with_x}" = "no" ; then
+      AC_MSG_RESULT(WIN32)
+      ac_cv_header_windows_h=yes
+      AC_DEFINE(XMD_H,[1],[Define to prevent redefinition of INT32 in jconfig.h])
+      AC_DEFINE(CYGWIN_USE_WIN32,[1],[Define to 1 if CYGWIN should use the WIN32 GUI])
+      LIBS="-L/usr/lib/w32api ${LIBS}" 
+      CFLAGS="-I/usr/include/w32api -D_WIN32 -DWIN32 ${CFLAGS}"
+      CXXFLAGS="-I/usr/include/w32api  -D_WIN32 -DWIN32 ${CXXFLAGS}"
+      CPPFLAGS="-I/usr/include/w32api  -D_WIN32 -DWIN32 ${CPPFLAGS}"
+    else
+      AC_MSG_RESULT(X11)
+    fi
+  fi
+])