diff --git a/filter-plugin/logstash-filter-mysql-aws-guardium/src/main/java/com/ibm/guardium/mysql/Parser.java b/filter-plugin/logstash-filter-mysql-aws-guardium/src/main/java/com/ibm/guardium/mysql/Parser.java
index 7c45bea7e..6d45eed40 100644
--- a/filter-plugin/logstash-filter-mysql-aws-guardium/src/main/java/com/ibm/guardium/mysql/Parser.java
+++ b/filter-plugin/logstash-filter-mysql-aws-guardium/src/main/java/com/ibm/guardium/mysql/Parser.java
@@ -146,7 +146,7 @@ private static Accessor getAccessor(Map data) {
         accessor.setDbProtocol(Constants.DB_PROTOCOL);
         accessor.setDbProtocolVersion(Constants.UNKNOWN_STRING);
         accessor.setOsUser(Constants.UNKNOWN_STRING);
-        accessor.setSourceProgram(null);
+        accessor.setSourceProgram(Constants.UNKNOWN_STRING);
         accessor.setClient_mac(Constants.UNKNOWN_STRING);
 
         // accountId:dbName