diff --git a/src/modules/module-sendspin-recv.c b/src/modules/module-sendspin-recv.c
index f76bfde6d..796520ce8 100644
--- a/src/modules/module-sendspin-recv.c
+++ b/src/modules/module-sendspin-recv.c
@@ -876,9 +876,14 @@ static int do_handle_binary(struct client *client, const uint8_t *payload, int s
 {
 	struct impl *impl = client->impl;
 	int32_t filled;
-	uint32_t index, length = size - 9;
+	uint32_t index, length;
 	uint64_t timestamp;
 
+	if (size < 9)
+		return 0;
+
+	length = size - 9;
+
 	if (payload[0] != 4 || client->stream == NULL)
 		return 0;