diff --git a/drivers/net/wireless/b43/pio.c b/drivers/net/wireless/b43/pio.c
index fcff923..279a53e 100644
--- a/drivers/net/wireless/b43/pio.c
+++ b/drivers/net/wireless/b43/pio.c
@@ -617,9 +617,19 @@
 	const char *err_msg = NULL;
 	struct b43_rxhdr_fw4 *rxhdr =
 		(struct b43_rxhdr_fw4 *)wl->pio_scratchspace;
+	size_t rxhdr_size = sizeof(*rxhdr);
 
 	BUILD_BUG_ON(sizeof(wl->pio_scratchspace) < sizeof(*rxhdr));
-	memset(rxhdr, 0, sizeof(*rxhdr));
+	switch (dev->fw.hdr_format) {
+	case B43_FW_HDR_410:
+	case B43_FW_HDR_351:
+		rxhdr_size -= sizeof(rxhdr->format_598) -
+			sizeof(rxhdr->format_351);
+		break;
+	case B43_FW_HDR_598:
+		break;
+	}
+	memset(rxhdr, 0, rxhdr_size);
 
 	/* Check if we have data and wait for it to get ready. */
 	if (q->rev >= 8) {
@@ -657,11 +667,11 @@
 
 	/* Get the preamble (RX header) */
 	if (q->rev >= 8) {
-		b43_block_read(dev, rxhdr, sizeof(*rxhdr),
+		b43_block_read(dev, rxhdr, rxhdr_size,
 			       q->mmio_base + B43_PIO8_RXDATA,
 			       sizeof(u32));
 	} else {
-		b43_block_read(dev, rxhdr, sizeof(*rxhdr),
+		b43_block_read(dev, rxhdr, rxhdr_size,
 			       q->mmio_base + B43_PIO_RXDATA,
 			       sizeof(u16));
 	}