diff --git a/monitor/analyze.c b/monitor/analyze.c
index b027b3c..eea3c9e 100644
--- a/monitor/analyze.c
+++ b/monitor/analyze.c
@@ -309,6 +309,9 @@ void analyze_trace(const char *path)
 		case BTSNOOP_OPCODE_SCO_RX_PKT:
 			sco_pkt(&tv, index, buf, pktlen);
 			break;
+		default:
+			fprintf(stderr, "Wrong opcode %u\n", opcode);
+			goto done;
 		}
 
 		num_packets++;