diff --git a/polymer/eduke32/source/jaudiolib/src/driver_sdl.c b/polymer/eduke32/source/jaudiolib/src/driver_sdl.c
index 82054ef38..a063ab169 100644
--- a/polymer/eduke32/source/jaudiolib/src/driver_sdl.c
+++ b/polymer/eduke32/source/jaudiolib/src/driver_sdl.c
@@ -65,6 +65,9 @@ static void fillData(int32_t chan, void *ptr, int32_t remaining, void *udata)
 
     UNREFERENCED_PARAMETER(chan);
     UNREFERENCED_PARAMETER(udata);
+    
+    if (!MixBuffer || !MixCallBack)
+      return;
 
     SDL_LockMutex(EffectFence);
 
@@ -152,8 +155,8 @@ int32_t SDLDrv_PCM_Init(int32_t *mixrate, int32_t *numchannels, int32_t *sampleb
     }
 
     chunksize = 512;
-
-    if (*mixrate >= 16000) chunksize *= 2;
+
+    if (*mixrate >= 16000) chunksize *= 2;
     if (*mixrate >= 32000) chunksize *= 2;
 
     err = Mix_OpenAudio(*mixrate, (*samplebits == 8) ? AUDIO_U8 : AUDIO_S16SYS, *numchannels, chunksize);