diff --git a/alsaaudio.c b/alsaaudio.c
index 7ca6a91..5d9a707 100644
--- a/alsaaudio.c
+++ b/alsaaudio.c
@@ -1465,9 +1465,10 @@ static PyObject *alsapcm_write(alsapcm_t *self, PyObject *args)
 	int res;
 	snd_pcm_state_t state = snd_pcm_state(self->handle);
 
+	Py_BEGIN_ALLOW_THREADS
+
 	if ((state != SND_PCM_STATE_XRUN && state != SND_PCM_STATE_SETUP) ||
 		(res = snd_pcm_prepare(self->handle)) >= 0) {
-		Py_BEGIN_ALLOW_THREADS
 		res = snd_pcm_writei(self->handle, data, datalen/self->framesize);
 		if (res == -EPIPE) {
 			/* EPIPE means underrun */