diff --git a/libmpcodecs/ad_pcm.c b/libmpcodecs/ad_pcm.c
index 20f33e14dc..e619793b86 100644
--- a/libmpcodecs/ad_pcm.c
+++ b/libmpcodecs/ad_pcm.c
@@ -21,6 +21,8 @@ LIBAD_EXTERN(pcm)
 static int init(sh_audio_t *sh_audio)
 {
   WAVEFORMATEX *h=sh_audio->wf;
+  if (!h)
+    return 0;
   sh_audio->i_bps=h->nAvgBytesPerSec;
   sh_audio->channels=h->nChannels;
   sh_audio->samplerate=h->nSamplesPerSec;