-AS_CASE(["$systems"], [*" ds "*], [
- AC_CHECK_HEADERS(mmsystem.h mmreg.h dsound.h,
+AS_CASE(["$systems"], [*" dsound "*], [
+ AC_CHECK_HEADERS(windows.h)
+ AC_CHECK_HEADERS(mmsystem.h mmreg.h dsound.h, [], [],
+[#ifdef HAVE_WINDOWS_H
+# include <windows.h>
+#endif])
+ AS_IF([test "x$ac_cv_header_windows_h" = xyes \
+ && test "x$ac_cv_header_mmsystem_h" = xyes \
+ && test "x$ac_cv_header_mmreg_h" = xyes \
+ && test "x$ac_cv_header_dsound_h" = xyes],