diff --git a/pom.xml b/pom.xml
index 48ae44ca..3cb2a61e 100644
--- a/pom.xml
+++ b/pom.xml
@@ -5,7 +5,7 @@
 
   <groupId>org.primeframework</groupId>
   <artifactId>prime-mvc</artifactId>
-  <version>5.1.1</version>
+  <version>5.2.0</version>
   <packaging>jar</packaging>
 
   <name>FusionAuth App</name>
diff --git a/src/main/java/org/primeframework/mvc/action/DefaultActionMappingWorkflow.java b/src/main/java/org/primeframework/mvc/action/DefaultActionMappingWorkflow.java
index 865b4536..2353aabe 100644
--- a/src/main/java/org/primeframework/mvc/action/DefaultActionMappingWorkflow.java
+++ b/src/main/java/org/primeframework/mvc/action/DefaultActionMappingWorkflow.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001-2024, Inversoft Inc., All Rights Reserved
+ * Copyright (c) 2001-2025, Inversoft Inc., All Rights Reserved
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -27,6 +27,7 @@
 import io.fusionauth.http.server.HTTPRequest;
 import io.fusionauth.http.server.HTTPResponse;
 import org.primeframework.mvc.NotAllowedException;
+import org.primeframework.mvc.NotImplementedException;
 import org.primeframework.mvc.http.HTTPTools;
 import org.primeframework.mvc.http.Status;
 import org.primeframework.mvc.parameter.fileupload.annotation.FileUpload;
@@ -93,7 +94,15 @@ public void perform(WorkflowChain chain) throws IOException {
     if (actionInvocation.action != null && actionInvocation.method == null) {
       Class<?> actionClass = actionInvocation.configuration.actionClass;
       logger.debug("The action class [{}] does not have a valid execute method for the HTTP method [{}]", actionClass.getCanonicalName(), method);
-      throw new NotAllowedException();
+
+      // Differentiate between not allowed for this action, vs not-implemented (supported by prime-mvc).
+      if (HTTPMethod.StandardMethods.containsKey(method.name())) {
+        throw new NotAllowedException();
+      }
+
+      // Note that the DefaultActionConfigurationBuilder will only resolve executeMethods for methods named in StandardMethods.
+      // See HTTPMethod.StandardMethods and DefaultActionConfigurationBuilder.findExecuteMethods
+      throw new NotImplementedException();
     }
 
     // Handle multipart file configuration
diff --git a/src/test/java/org/primeframework/mvc/GlobalTest.java b/src/test/java/org/primeframework/mvc/GlobalTest.java
index 16b112c2..40f9f580 100644
--- a/src/test/java/org/primeframework/mvc/GlobalTest.java
+++ b/src/test/java/org/primeframework/mvc/GlobalTest.java
@@ -1465,7 +1465,11 @@ public void notAllowed() {
   public void notImplemented() {
     simulator.test("/not-allowed")
              .method("POTATO")
-             .assertStatusCode(405) // Not allowed since we can handle any name but the action doesn't have that method
+             // We currently only map out execute methods in the action that are named by a method
+             // defined in the HTTPMethod.StandardMethods. If an action does not define a standard HTTP
+             // method, a 405 will be returned. If you ask for a non-standard method that is not implemented
+             // by prime-mvc, you will receive a 501.
+             .assertStatusCode(501)
              .assertHeaderContains("Cache-Control", "no-cache");
   }