diff --git a/lib/serialport-parsers.js b/lib/serialport-parsers.js
index 776474c..33d56a3 100644
--- a/lib/serialport-parsers.js
+++ b/lib/serialport-parsers.js
@@ -39,7 +39,7 @@ function onCSQ(data) {
     return val[1];
 }
 
-function onPdu(data, parsedData) {
+function onPduDeliver(data, parsedData) {
     const from = parsedData.getAddress && parsedData.getAddress().getPhone
         ? parsedData.getAddress().getPhone() : null;
 
@@ -99,9 +99,13 @@ parserReadline.on('data', (data) => {
         logger.verbose('PDU parsed', { type: (typeof pduParsed.getType === 'function') && pduParsed.getType() });
     }
 
-    if (pduParsed && pduParsed.getType && pduParsed.getType().getSrr()) {
+    if (pduParsed && pduParsed.constructor.name !== 'Deliver') {
+        logger.warn('Unknown PDU message type name', { typeName: pduParsed.constructor.name, type: pduParsed.getType(), data: data.toString().trim() });
+    }
+
+    if (pduParsed && pduParsed.constructor.name === 'Deliver' && pduParsed.getType && pduParsed.getType().getSrr()) {
         logger.verbose('Got a PDU SMS-DELIVER', { type: pduParsed.getType() });
-        onPdu(data, pduParsed);
+        onPduDeliver(data, pduParsed);
     } else if (isResultCodeIs(data, 'CSQ')) {
         logger.verbose('Got a signal quality report', { data: data.toString() });
         onCSQ(data);