diff --git a/grade/lib.php b/grade/lib.php
index b03820624f9..491d92e2a5c 100644
--- a/grade/lib.php
+++ b/grade/lib.php
@@ -887,6 +887,15 @@ function grade_get_plugin_info($courseid, $active_type, $active_plugin) {
         $plugin_info['export'] = $exports;
     }
 
+    // Let other plugins add plugins here so that we get extra tabs
+    // in the gradebook.
+    $callbacks = get_plugins_with_function('extend_gradebook_plugininfo', 'lib.php');
+    foreach ($callbacks as $plugins) {
+        foreach ($plugins as $pluginfunction) {
+            $plugin_info = $pluginfunction($plugin_info, $courseid);
+        }
+    }
+
     foreach ($plugin_info as $plugin_type => $plugins) {
         if (!empty($plugins->id) && $active_plugin == $plugins->id) {
             $plugin_info['strings']['active_plugin_str'] = $plugins->string;
diff --git a/grade/upgrade.txt b/grade/upgrade.txt
index cc49aa9967a..a6559d0eda6 100644
--- a/grade/upgrade.txt
+++ b/grade/upgrade.txt
@@ -1,6 +1,11 @@
 This file describes API changes in /grade/* ;
 Information provided here is intended especially for developers.
 
+=== 4.0 ===
+
+* There is a new callback inside of grade_get_plugin_info called extend_gradebook_plugininfo
+  which allows for new tabs to be added to the gradebook.
+
 === 3.7 ===
 
 * The grade_cron() function has been removed. Please use grade_history_cleanup_task and grade_cron_task scheduled tasks instead.