diff --git a/modules/audio_output/directx.c b/modules/audio_output/directx.c
index 36ffe89d7590f8cf0a1403edabe56e947747448f..228d800bb3711b089e03ea2de4fd32a9974ddf85 100644
--- a/modules/audio_output/directx.c
+++ b/modules/audio_output/directx.c
@@ -467,8 +467,6 @@ static void Probe( audio_output_t * p_aout, const audio_sample_format_t *fmt )
         var_Destroy( p_aout, "audio-device" );
         return;
     }
-
-    var_AddCallback( p_aout, "audio-device", aout_ChannelsRestart, NULL );
 }
 
 /*****************************************************************************
diff --git a/modules/audio_output/kai.c b/modules/audio_output/kai.c
index 18985dcd966bd0e20d43cbd6e8baf8770f0c6e98..f09c57f6fa3aa6ccfd7d1da4b66098cc67164af5 100644
--- a/modules/audio_output/kai.c
+++ b/modules/audio_output/kai.c
@@ -251,7 +251,6 @@ static int Start ( audio_output_t *p_aout, audio_sample_format_t *fmt )
             val.i_int = AOUT_VAR_MONO;
         }
         var_Change( p_aout, "audio-device", VLC_VAR_SETDEFAULT, &val, NULL );
-        var_AddCallback( p_aout, "audio-device", aout_ChannelsRestart, NULL );
     }
 
     /* Prevent SIG_FPE */