diff --git a/src/__phutil_library_map__.php b/src/__phutil_library_map__.php
--- a/src/__phutil_library_map__.php
+++ b/src/__phutil_library_map__.php
@@ -1437,7 +1437,6 @@
     'PhabricatorChatLogController' => 'applications/chatlog/controller/PhabricatorChatLogController.php',
     'PhabricatorChatLogDAO' => 'applications/chatlog/storage/PhabricatorChatLogDAO.php',
     'PhabricatorChatLogEvent' => 'applications/chatlog/storage/PhabricatorChatLogEvent.php',
-    'PhabricatorChatLogEventType' => 'applications/chatlog/constants/PhabricatorChatLogEventType.php',
     'PhabricatorChatLogQuery' => 'applications/chatlog/query/PhabricatorChatLogQuery.php',
     'PhabricatorCommitBranchesField' => 'applications/repository/customfield/PhabricatorCommitBranchesField.php',
     'PhabricatorCommitCustomField' => 'applications/repository/customfield/PhabricatorCommitCustomField.php',
@@ -4590,7 +4589,6 @@
       'PhabricatorChatLogDAO',
       'PhabricatorPolicyInterface',
     ),
-    'PhabricatorChatLogEventType' => 'PhabricatorChatLogConstants',
     'PhabricatorChatLogQuery' => 'PhabricatorCursorPagedPolicyAwareQuery',
     'PhabricatorCommitBranchesField' => 'PhabricatorCommitCustomField',
     'PhabricatorCommitCustomField' => 'PhabricatorCustomField',
diff --git a/src/applications/chatlog/constants/PhabricatorChatLogEventType.php b/src/applications/chatlog/constants/PhabricatorChatLogEventType.php
deleted file mode 100644
--- a/src/applications/chatlog/constants/PhabricatorChatLogEventType.php
+++ /dev/null
@@ -1,8 +0,0 @@
-<?php
-
-final class PhabricatorChatLogEventType
-  extends PhabricatorChatLogConstants {
-
-  const TYPE_MESSAGE = 'mesg';
-
-}