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
@@ -972,7 +972,6 @@
     'phutil_count' => 'internationalization/pht.php',
     'phutil_date_format' => 'utils/viewutils.php',
     'phutil_decode_mime_header' => 'utils/utils.php',
-    'phutil_deprecated' => 'init/lib/moduleutils.php',
     'phutil_describe_type' => 'utils/utils.php',
     'phutil_encode_log' => 'utils/utils.php',
     'phutil_error_listener_example' => 'error/phlog.php',
diff --git a/src/error/PhutilErrorHandler.php b/src/error/PhutilErrorHandler.php
--- a/src/error/PhutilErrorHandler.php
+++ b/src/error/PhutilErrorHandler.php
@@ -425,16 +425,6 @@
           $metadata['file'],
           $metadata['line']);
 
-        $metadata['default_message'] = $default_message;
-        error_log($default_message);
-        break;
-      case self::DEPRECATED:
-        $default_message = sprintf(
-          '[%s] DEPRECATED: %s is deprecated; %s',
-          $timestamp,
-          $value,
-          $metadata['why']);
-
         $metadata['default_message'] = $default_message;
         error_log($default_message);
         break;
diff --git a/src/init/lib/moduleutils.php b/src/init/lib/moduleutils.php
--- a/src/init/lib/moduleutils.php
+++ b/src/init/lib/moduleutils.php
@@ -36,18 +36,6 @@
   return phutil_get_library_name_for_root($root);
 }
 
-/**
- * Warns about use of deprecated behavior.
- */
-function phutil_deprecated($what, $why) {
-  PhutilErrorHandler::dispatchErrorMessage(
-    PhutilErrorHandler::DEPRECATED,
-    $what,
-    array(
-      'why' => $why,
-    ));
-}
-
 function phutil_load_library($path) {
   PhutilBootloader::getInstance()->loadLibrary($path);
 }