diff --git a/drivers/firewire/core-iso.c b/drivers/firewire/core-iso.c
index 8382e27..38c0aa6 100644
--- a/drivers/firewire/core-iso.c
+++ b/drivers/firewire/core-iso.c
@@ -146,7 +146,7 @@
 /* Convert DMA address to offset into virtually contiguous buffer. */
 size_t fw_iso_buffer_lookup(struct fw_iso_buffer *buffer, dma_addr_t completed)
 {
-	int i;
+	size_t i;
 	dma_addr_t address;
 	ssize_t offset;