diff --git a/tools/btsnoop.c b/tools/btsnoop.c
index efaa45d..0bd28b6 100644
--- a/tools/btsnoop.c
+++ b/tools/btsnoop.c
@@ -448,7 +448,7 @@ next_packet:
 		acl_flags = buf[2] >> 4;
 
 		/* use only packet with ACL start flag */
-		if (acl_flags & 0x02) {
+		if ((acl_flags & 0x02) && len > 9) {
 			if (current_cid == 0x0040 && pdu_len > 0) {
 				int i;
 				if (!pdu_first)
@@ -472,7 +472,7 @@ next_packet:
 			current_cid = buf[8] << 8 | buf[7];
 			memcpy(pdu_buf, buf + 9, len - 9);
 			pdu_len = len - 9;
-		} else if (acl_flags & 0x01) {
+		} else if ((acl_flags & 0x01) && len > 5) {
 			memcpy(pdu_buf + pdu_len, buf + 5, len - 5);
 			pdu_len += len - 5;
 		}