diff --git a/libao2/audio_out.c b/libao2/audio_out.c
index c7999415e4..59c30295dd 100644
--- a/libao2/audio_out.c
+++ b/libao2/audio_out.c
@@ -23,7 +23,6 @@ extern ao_functions_t audio_out_openal;
 extern ao_functions_t audio_out_null;
  extern ao_functions_t audio_out_alsa5;
  extern ao_functions_t audio_out_alsa;
- extern ao_functions_t audio_out_alsa;
 extern ao_functions_t audio_out_nas;
 extern ao_functions_t audio_out_sdl;
 extern ao_functions_t audio_out_sun;