-case "$opsys" in mingw*) mingw_include=`eval "gcc -print-file-name=libc.a"` ;
- mingw_include=`eval "dirname $mingw_include"` ;
- mingw_include="-I$mingw_include/../include/mingw32" ;
- c_switch_system="$c_switch_system $mingw_include" && if test "$extra_verbose" = "yes"; then echo " Appending \"$mingw_include\" to \$c_switch_system"; fi ;;
+case "$opsys" in mingw* | cygwin*)
+ cygwin_include=`eval "gcc -print-file-name=libc.a"` ;
+ cygwin_include=`eval "dirname $cygwin_include"` ;
+ cygwin_include="-I$cygwin_include/../include" ;
+ extra_includes="$cygwin_include/mingw32 $cygwin_include/mingw $cygwin_include" ;
+ case "$opsys" in mingw*)
+ c_switch_system="$c_switch_system $extra_includes" && if test "$extra_verbose" = "yes"; then echo " Appending \"$extra_includes\" to \$c_switch_system"; fi ;;
+ esac
+ ;;