diff --git a/drivers/macintosh/rack-meter.c b/drivers/macintosh/rack-meter.c
index 7755271..25852e3 100644
--- a/drivers/macintosh/rack-meter.c
+++ b/drivers/macintosh/rack-meter.c
@@ -154,8 +154,8 @@
 		DBDMA_DO_STOP(rm->dma_regs);
 		return;
 	}
-	memset(rdma->buf1, 0, ARRAY_SIZE(rdma->buf1));
-	memset(rdma->buf2, 0, ARRAY_SIZE(rdma->buf2));
+	memset(rdma->buf1, 0, sizeof(rdma->buf1));
+	memset(rdma->buf2, 0, sizeof(rdma->buf2));
 
 	rm->dma_buf_v->mark = 0;