diff --git a/drivers/firewire/core-cdev.c b/drivers/firewire/core-cdev.c
index 8be720b..bbb8160 100644
--- a/drivers/firewire/core-cdev.c
+++ b/drivers/firewire/core-cdev.c
@@ -968,7 +968,8 @@
 			if (ctx->header_size == 0) {
 				if (u.packet.header_length > 0)
 					return -EINVAL;
-			} else if (u.packet.header_length % ctx->header_size != 0) {
+			} else if (u.packet.header_length == 0 ||
+				   u.packet.header_length % ctx->header_size != 0) {
 				return -EINVAL;
 			}
 			header_length = 0;