diff --git a/drivers/firmware/sigma.c b/drivers/firmware/sigma.c
index c780baa59ed9..36265de0a9e8 100644
--- a/drivers/firmware/sigma.c
+++ b/drivers/firmware/sigma.c
@@ -130,7 +130,8 @@ int process_sigma_firmware(struct i2c_client *client, const char *name)
 	if (memcmp(ssfw_head->magic, SIGMA_MAGIC, ARRAY_SIZE(ssfw_head->magic)))
 		goto done;
 
-	crc = crc32(0, fw->data, fw->size);
+	crc = crc32(0, fw->data + sizeof(*ssfw_head),
+			fw->size - sizeof(*ssfw_head));
 	pr_debug("%s: crc=%x\n", __func__, crc);
 	if (crc != ssfw_head->crc)
 		goto done;