-#if HAVE_ALSA_ASOUNDLIB_H
-# define DEFAULT_BACKEND playrtp_alsa
-#elif HAVE_SYS_SOUNDCARD_H || EMPEG_HOST
-# define DEFAULT_BACKEND playrtp_oss
-#elif HAVE_COREAUDIO_AUDIOHARDWARE_H
-# define DEFAULT_BACKEND playrtp_coreaudio
-#else
-# error No known backend
+#if DEFAULT_BACKEND == BACKEND_ALSA
+# define DEFAULT_PLAYRTP_BACKEND playrtp_alsa
+#elif DEFAULT_BACKEND == BACKEND_OSS
+# define DEFAULT_PLAYRTP_BACKEND playrtp_oss
+#elif DEFAULT_BACKEND == BACKEND_COREAUDIO
+# define DEFAULT_PLAYRTP_BACKEND playrtp_coreaudio