diff --git a/src/pcm/pcm_params.c b/src/pcm/pcm_params.c
index 3e7f92d8..631e2652 100644
--- a/src/pcm/pcm_params.c
+++ b/src/pcm/pcm_params.c
@@ -2288,6 +2288,7 @@ int _snd_pcm_hw_params(snd_pcm_t *pcm, snd_pcm_hw_params_t *params)
 	pcm->fifo_size = params->fifo_size;
 	
 	/* Default sw params */
+	memset(&sw, 0, sizeof(sw));
 	snd_pcm_sw_params_default(pcm, &sw);
 	err = snd_pcm_sw_params(pcm, &sw);
 	assert(err >= 0);