diff --git a/lib/protocol/pdu.js b/lib/protocol/pdu.js
index 0a7e170..892a2c9 100644
--- a/lib/protocol/pdu.js
+++ b/lib/protocol/pdu.js
@@ -291,8 +291,9 @@ SnmpTrapV1PDU(arg)
 		this.agent_addr = arg.agent_addr;
 	if (arg.generic_trap)
 		this.generic_trap = arg.generic_trap;
-	if (arg.specific_trap)
-		this.specific_trap = arg.specific_trap;
+	// issue #247
+        // if (arg.specific_trap)
+		this.specific_trap = arg.specific_trap || 0;
 	if (arg.time_stamp)
 		this.time_stamp = arg.time_stamp;
 }