diff --git a/sound/pci/bt87x.c b/sound/pci/bt87x.c
index 188c7cf..131952f 100644
--- a/sound/pci/bt87x.c
+++ b/sound/pci/bt87x.c
@@ -157,7 +157,7 @@
 	int dig_rate;
 
 	spinlock_t reg_lock;
-	long opened;
+	unsigned long opened;
 	struct snd_pcm_substream *substream;
 
 	struct snd_dma_buffer dma_risc;