diff --git a/src/main/java/org/opensearch/securityanalytics/model/Detector.java b/src/main/java/org/opensearch/securityanalytics/model/Detector.java
index a126b5fdb..b60d7de9e 100644
--- a/src/main/java/org/opensearch/securityanalytics/model/Detector.java
+++ b/src/main/java/org/opensearch/securityanalytics/model/Detector.java
@@ -167,12 +167,12 @@ public Detector(StreamInput sin) throws IOException {
                 sin.readList(DetectorInput::readFrom),
                 sin.readList(DetectorTrigger::readFrom),
                 sin.readStringList(),
-                sin.readString(),
-                sin.readString(),
-                sin.readString(),
-                sin.readString(),
-                sin.readString(),
-                sin.readString(),
+                sin.readOptionalString(),
+                sin.readOptionalString(),
+                sin.readOptionalString(),
+                sin.readOptionalString(),
+                sin.readOptionalString(),
+                sin.readOptionalString(),
                 sin.readMap(StreamInput::readString, StreamInput::readString),
                 sin.readStringList(),
                 sin.readBoolean()
@@ -207,12 +207,12 @@ public void writeTo(StreamOutput out) throws IOException {
             it.writeTo(out);
         }
         out.writeStringCollection(monitorIds);
-        out.writeString(ruleIndex);
-        out.writeString(alertsIndex);
-        out.writeString(alertsHistoryIndex);
-        out.writeString(alertsHistoryIndexPattern);
-        out.writeString(findingsIndex);
-        out.writeString(findingsIndexPattern);
+        out.writeOptionalString(ruleIndex);
+        out.writeOptionalString(alertsIndex);
+        out.writeOptionalString(alertsHistoryIndex);
+        out.writeOptionalString(alertsHistoryIndexPattern);
+        out.writeOptionalString(findingsIndex);
+        out.writeOptionalString(findingsIndexPattern);
         out.writeMap(ruleIdMonitorIdMap, StreamOutput::writeString, StreamOutput::writeString);
 
         if (workflowIds != null) {