diff --git a/inc/Gtfs/Calendar_CalendarDay.php b/inc/Gtfs/Calendar_CalendarDay.php
new file mode 100644
index 0000000..00964cc
--- /dev/null
+++ b/inc/Gtfs/Calendar_CalendarDay.php
@@ -0,0 +1,16 @@
+<?php
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: proto/gtfs.proto
+
+namespace Gtfs;
+
+if (false) {
+    /**
+     * This class is deprecated. Use Gtfs\Calendar\CalendarDay instead.
+     * @deprecated
+     */
+    class Calendar_CalendarDay {}
+}
+class_exists(Calendar\CalendarDay::class);
+@trigger_error('Gtfs\Calendar_CalendarDay is deprecated and will be removed in the next major release. Use Gtfs\Calendar\CalendarDay instead', E_USER_DEPRECATED);
+