diff --git a/server/src/main/java/org/opensearch/script/Script.java b/server/src/main/java/org/opensearch/script/Script.java
index 9e74314c281cd..f18bd992cb00d 100644
--- a/server/src/main/java/org/opensearch/script/Script.java
+++ b/server/src/main/java/org/opensearch/script/Script.java
@@ -589,7 +589,7 @@ public Script(StreamInput in) throws IOException {
         @SuppressWarnings("unchecked")
         Map<String, String> options = (Map<String, String>) (Map) in.readMap();
         this.options = options;
-        this.params = in.readMap();
+        this.params = Collections.unmodifiableMap(in.readMap());
     }
 
     @Override
diff --git a/server/src/main/java/org/opensearch/script/UpdateScript.java b/server/src/main/java/org/opensearch/script/UpdateScript.java
index 86697e9ae550e..f6355fe24817b 100644
--- a/server/src/main/java/org/opensearch/script/UpdateScript.java
+++ b/server/src/main/java/org/opensearch/script/UpdateScript.java
@@ -32,6 +32,7 @@
 
 package org.opensearch.script;
 
+import java.util.Collections;
 import java.util.Map;
 
 /**
@@ -53,7 +54,7 @@ public abstract class UpdateScript {
     private final Map<String, Object> ctx;
 
     public UpdateScript(Map<String, Object> params, Map<String, Object> ctx) {
-        this.params = params;
+        this.params = Collections.unmodifiableMap(params);
         this.ctx = ctx;
     }