diff --git a/lib/db/upgrade.php b/lib/db/upgrade.php
index b80caa22ab7..fe226911a47 100644
--- a/lib/db/upgrade.php
+++ b/lib/db/upgrade.php
@@ -6651,6 +6651,17 @@ FROM
         upgrade_main_savepoint(true, 2011071300.01);
     }
 
+    if ($oldversion < 2011081700.01) {
+        // Remove category_sortorder index that was supposed to be removed long time ago
+        $table = new xmldb_table('course');
+        $index = new xmldb_index('category_sortorder', XMLDB_INDEX_UNIQUE, array('category', 'sortorder'));
+
+        if ($dbman->index_exists($table, $index)) {
+            $dbman->drop_index($table, $index);
+        }
+        upgrade_main_savepoint(true, 2011081700.01);
+    }
+
 
     return true;
 }
diff --git a/version.php b/version.php
index f211fd490f2..1b2578a8bfd 100644
--- a/version.php
+++ b/version.php
@@ -31,7 +31,7 @@ defined('MOODLE_INTERNAL') || die();
 
 
 
-$version  = 2011081700.00;              // YYYYMMDD      = weekly release date of this DEV branch
+$version  = 2011081700.01;              // YYYYMMDD      = weekly release date of this DEV branch
                                         //         RR    = release increments - 00 in DEV branches
                                         //           .XX = incremental changes