diff --git a/src/drivers/fluid_dsound.c b/src/drivers/fluid_dsound.c
index 00cb791e..dfdcdb92 100644
--- a/src/drivers/fluid_dsound.c
+++ b/src/drivers/fluid_dsound.c
@@ -184,7 +184,7 @@ void fluid_dsound_audio_driver_settings(fluid_settings_t *settings)
 fluid_audio_driver_t *
 new_fluid_dsound_audio_driver(fluid_settings_t *settings, fluid_synth_t *synth)
 {
-    return new_fluid_dsound_audio_driver2(settings, (fluid_audio_func_t)fluid_synth_process, synth);
+    return new_fluid_dsound_audio_driver2(settings, NULL, synth);
 }
 
 fluid_audio_driver_t *
diff --git a/src/drivers/fluid_waveout.c b/src/drivers/fluid_waveout.c
index 5e91f84f..6f0684c7 100644
--- a/src/drivers/fluid_waveout.c
+++ b/src/drivers/fluid_waveout.c
@@ -266,7 +266,7 @@ void fluid_waveout_audio_driver_settings(fluid_settings_t *settings)
 fluid_audio_driver_t *
 new_fluid_waveout_audio_driver(fluid_settings_t *settings, fluid_synth_t *synth)
 {
-    return new_fluid_waveout_audio_driver2(settings, (fluid_audio_func_t)fluid_synth_process, synth);
+    return new_fluid_waveout_audio_driver2(settings, NULL, synth);
 }
 
 fluid_audio_driver_t *