diff --git a/DEVELOPER_GUIDE.md b/DEVELOPER_GUIDE.md
index b56c3e9d..43a3eefe 100644
--- a/DEVELOPER_GUIDE.md
+++ b/DEVELOPER_GUIDE.md
@@ -304,7 +304,7 @@ The artifact will include extension settings for the sample Hello World extensio
 ```
 
 You can optionally add `routeNamePrefix:` as a value to the yml. This setting allows you to prefix all your registered NamedRoute names.
-The value must be alphanumeric and can contain `-`, `_` in the name.
+The value must be alphanumeric and can contain `_` in the name.
 
 Start the sample extension with `./bin/opensearch-sdk-java`
 
diff --git a/src/main/java/org/opensearch/sdk/rest/BaseExtensionRestHandler.java b/src/main/java/org/opensearch/sdk/rest/BaseExtensionRestHandler.java
index 5f11ab3b..d4067011 100644
--- a/src/main/java/org/opensearch/sdk/rest/BaseExtensionRestHandler.java
+++ b/src/main/java/org/opensearch/sdk/rest/BaseExtensionRestHandler.java
@@ -44,7 +44,7 @@
  */
 public abstract class BaseExtensionRestHandler implements ExtensionRestHandler {
 
-    private static final String VALID_ROUTE_PREFIX_PATTERN = "^[a-zA-Z0-9-_]*$";
+    private static final String VALID_ROUTE_PREFIX_PATTERN = "^[a-zA-Z0-9_]*$";
 
     private String routeNamePrefix;
 
@@ -89,8 +89,7 @@ public void setRouteNamePrefix(String prefix) {
         // we by-pass null assignment as routeNamePrefixes are not mandatory
         if (prefix != null && !prefix.matches(VALID_ROUTE_PREFIX_PATTERN)) {
             throw new OpenSearchException(
-                "Invalid route name prefix specified. The prefix may include the following characters"
-                    + " 'a-z', 'A-Z', '0-9', ':', '/', '*', '_'"
+                "Invalid route name prefix specified. The prefix may include the following characters" + " 'a-z', 'A-Z', '0-9', '_'"
             );
         }
         routeNamePrefix = prefix;