diff --git a/includes/Defines.php b/includes/Defines.php
new file mode 100644
index 00000000000..6a5c3915a25
--- /dev/null
+++ b/includes/Defines.php
@@ -0,0 +1,34 @@
+<?php
+# A few constants that might be needed during LocalSettings.php
+
+define( 'DBO_DEBUG', 1 );
+define( 'DBO_NOBUFFER', 2 );
+define( 'DBO_IGNORE', 4 );
+define( 'DBO_TRX', 8 );
+define( 'DBO_DEFAULT', 16 );
+
+# Virtual namespaces; these don't appear in the page database:
+define("NS_MEDIA", -2);
+define("NS_SPECIAL", -1);
+
+# Real namespaces:
+define("NS_MAIN", 0);
+define("NS_TALK", 1);
+define("NS_USER", 2);
+define("NS_USER_TALK", 3);
+define("NS_WP", 4);
+define("NS_WIKIPEDIA", 4);
+define("NS_WP_TALK", 5);
+define("NS_WIKIPEDIA_TALK", 5);
+define("NS_IMAGE", 6);
+define("NS_IMAGE_TALK", 7);
+define("NS_MEDIAWIKI", 8);
+define("NS_MEDIAWIKI_TALK", 9);
+define("NS_TEMPLATE", 10);
+define("NS_TEMPLATE_TALK", 11);
+define("NS_HELP", 12);
+define("NS_HELP_TALK", 13);
+define("NS_CATEGORY", 14);
+define("NS_CATEGORY_TALK", 15);
+
+?>