diff --git a/drivers/staging/line6/playback.c b/drivers/staging/line6/playback.c
index 29940fd..10c5438 100644
--- a/drivers/staging/line6/playback.c
+++ b/drivers/staging/line6/playback.c
@@ -246,7 +246,7 @@
 
 	change_volume(urb_out, line6pcm->volume_playback, bytes_per_frame);
 
-	if (line6pcm->prev_fbuf != 0) {
+	if (line6pcm->prev_fbuf != NULL) {
 #ifdef CONFIG_LINE6_USB_IMPULSE_RESPONSE
 		if (line6pcm->flags & MASK_PCM_IMPULSE) {
 			create_impulse_test_signal(line6pcm, urb_out,