diff --git a/lib/db/services.php b/lib/db/services.php
index 10bd788f3bd..36bdc0794f4 100644
--- a/lib/db/services.php
+++ b/lib/db/services.php
@@ -917,7 +917,8 @@ $functions = array(
         'classname' => 'core_message_external',
         'methodname' => 'delete_conversation',
         'classpath' => 'message/externallib.php',
-        'description' => 'Deletes a conversation.',
+        'description' => '** DEPRECATED ** Please do not call this function any more.
+                          Deletes a conversation.',
         'type' => 'write',
         'capabilities' => 'moodle/site:deleteownmessage',
         'ajax' => true,
diff --git a/message/externallib.php b/message/externallib.php
index 32185bab3c1..e5073b5296e 100644
--- a/message/externallib.php
+++ b/message/externallib.php
@@ -2541,6 +2541,7 @@ class core_message_external extends external_api {
     /**
      * Returns description of method parameters.
      *
+     * @deprecated since 3.6
      * @return external_function_parameters
      * @since 3.2
      */
@@ -2556,6 +2557,7 @@ class core_message_external extends external_api {
     /**
      * Deletes a conversation.
      *
+     * @deprecated since 3.6
      * @param int $userid The user id of who we want to delete the conversation for
      * @param int $otheruserid The user id of the other user in the conversation
      * @return array
@@ -2609,6 +2611,7 @@ class core_message_external extends external_api {
     /**
      * Returns description of method result value.
      *
+     * @deprecated since 3.6
      * @return external_description
      * @since 3.2
      */
@@ -2621,6 +2624,15 @@ class core_message_external extends external_api {
         );
     }
 
+    /**
+     * Marking the method as deprecated.
+     *
+     * @return bool
+     */
+    public static function delete_conversation_is_deprecated() {
+        return true;
+    }
+
     /**
      * Returns description of method parameters
      *
@@ -3017,7 +3029,6 @@ class core_message_external extends external_api {
         );
     }
 
-
     /**
      * Returns description of method parameters
      *
diff --git a/message/upgrade.txt b/message/upgrade.txt
index c95b7348bfc..969e3b7bfda 100644
--- a/message/upgrade.txt
+++ b/message/upgrade.txt
@@ -32,9 +32,10 @@ information provided here is intended especially for developers.
 * The method \core_message\api::can_delete_conversation() now expects a 'conversationid' to be passed
   as the second parameter.
 * The following web services have been deprecated. Please do not call these any more.
-  - core_message_external::block_contacts, please use core_message_external::block_user instead.
-  - core_message_external::unblock_contacts, please use core_message_external::unblock_user instead.
-  - core_message_external::create_contacts, please use core_message_external::create_contact_request instead.
+  - core_message_external::block_contacts(), please use core_message_external::block_user() instead.
+  - core_message_external::unblock_contacts(), please use core_message_external::unblock_user() instead.
+  - core_message_external::create_contacts(), please use core_message_external::create_contact_request() instead.
+  - core_message_external::delete_conversation(), please use core_message_external::delete_conversation_by_id() instead.
 
 === 3.5 ===