diff --git a/attrib/att.c b/attrib/att.c
index a8f641a..472c25c 100644
--- a/attrib/att.c
+++ b/attrib/att.c
@@ -161,7 +161,7 @@ uint16_t dec_read_by_grp_req(const uint8_t *pdu, size_t len, uint16_t *start,
 	if (pdu[0] != ATT_OP_READ_BY_GROUP_REQ)
 		return 0;
 
-	if (len < min_len + 2)
+	if (len != (min_len + 2) && len != (min_len + 16))
 		return 0;
 
 	*start = att_get_u16(&pdu[1]);