diff --git a/lib/classes/plugin_manager.php b/lib/classes/plugin_manager.php
index 254e04f2281..757b21985e1 100644
--- a/lib/classes/plugin_manager.php
+++ b/lib/classes/plugin_manager.php
@@ -375,13 +375,13 @@ class core_plugin_manager {
         if (!isset($types[$type])) {
             // Orphaned subplugins!
             $plugintypeclass = static::resolve_plugininfo_class($type);
-            $this->pluginsinfo[$type] = $plugintypeclass::get_plugins($type, null, $plugintypeclass);
+            $this->pluginsinfo[$type] = $plugintypeclass::get_plugins($type, null, $plugintypeclass, $this);
             return $this->pluginsinfo[$type];
         }
 
         /** @var \core\plugininfo\base $plugintypeclass */
         $plugintypeclass = static::resolve_plugininfo_class($type);
-        $plugins = $plugintypeclass::get_plugins($type, $types[$type], $plugintypeclass);
+        $plugins = $plugintypeclass::get_plugins($type, $types[$type], $plugintypeclass, $this);
         $this->pluginsinfo[$type] = $plugins;
 
         return $this->pluginsinfo[$type];
diff --git a/lib/classes/plugininfo/base.php b/lib/classes/plugininfo/base.php
index 71f0187fe9d..fae917a6153 100644
--- a/lib/classes/plugininfo/base.php
+++ b/lib/classes/plugininfo/base.php
@@ -61,6 +61,8 @@ abstract class base {
     public $instances;
     /** @var int order of the plugin among other plugins of the same type - not supported yet */
     public $sortorder;
+    /** @var core_plugin_manager the plugin manager this plugin info is part of */
+    public $pluginman;
 
     /** @var array|null array of {@link \core\update\info} for this plugin */
     protected $availableupdates;
@@ -77,23 +79,26 @@ abstract class base {
      * Gathers and returns the information about all plugins of the given type,
      * either on disk or previously installed.
      *
+     * This is supposed to be used exclusively by the plugin manager when it is
+     * populating its tree of plugins.
+     *
      * @param string $type the name of the plugintype, eg. mod, auth or workshopform
      * @param string $typerootdir full path to the location of the plugin dir
      * @param string $typeclass the name of the actually called class
+     * @param core_plugin_manager $pluginman the plugin manager calling this method
      * @return array of plugintype classes, indexed by the plugin name
      */
-    public static function get_plugins($type, $typerootdir, $typeclass) {
+    public static function get_plugins($type, $typerootdir, $typeclass, $pluginman) {
         // Get the information about plugins at the disk.
         $plugins = core_component::get_plugin_list($type);
         $return = array();
         foreach ($plugins as $pluginname => $pluginrootdir) {
             $return[$pluginname] = self::make_plugin_instance($type, $typerootdir,
-                $pluginname, $pluginrootdir, $typeclass);
+                $pluginname, $pluginrootdir, $typeclass, $pluginman);
         }
 
         // Fetch missing incorrectly uninstalled plugins.
-        $manager = core_plugin_manager::instance();
-        $plugins = $manager->get_installed_plugins($type);
+        $plugins = $pluginman->get_installed_plugins($type);
 
         foreach ($plugins as $name => $version) {
             if (isset($return[$name])) {
@@ -106,6 +111,7 @@ abstract class base {
             $plugin->rootdir     = null;
             $plugin->displayname = $name;
             $plugin->versiondb   = $version;
+            $plugin->pluginman   = $pluginman;
             $plugin->init_is_standard();
 
             $return[$name] = $plugin;
@@ -122,14 +128,16 @@ abstract class base {
      * @param string $name the plugin name, eg. 'workshop'
      * @param string $namerootdir full path to the location of the plugin
      * @param string $typeclass the name of class that holds the info about the plugin
+     * @param core_plugin_manager $pluginman the plugin manager of the new instance
      * @return base the instance of $typeclass
      */
-    protected static function make_plugin_instance($type, $typerootdir, $name, $namerootdir, $typeclass) {
+    protected static function make_plugin_instance($type, $typerootdir, $name, $namerootdir, $typeclass, $pluginman) {
         $plugin              = new $typeclass();
         $plugin->type        = $type;
         $plugin->typerootdir = $typerootdir;
         $plugin->name        = $name;
         $plugin->rootdir     = $namerootdir;
+        $plugin->pluginman   = $pluginman;
 
         $plugin->init_display_name();
         $plugin->load_disk_version();
@@ -206,7 +214,7 @@ abstract class base {
      * data) or is missing from disk.
      */
     public function load_disk_version() {
-        $versions = core_plugin_manager::instance()->get_present_plugins($this->type);
+        $versions = $this->pluginman->get_present_plugins($this->type);
 
         $this->versiondisk = null;
         $this->versionrequires = null;
@@ -260,7 +268,7 @@ abstract class base {
      * @return string|bool false if not a subplugin, name of the parent otherwise
      */
     public function get_parent_plugin() {
-        return $this->get_plugin_manager()->get_parent_of_subplugin($this->type);
+        return $this->pluginman->get_parent_of_subplugin($this->type);
     }
 
     /**
@@ -272,7 +280,7 @@ abstract class base {
      * data) or has not been installed yet.
      */
     public function load_db_version() {
-        $versions = core_plugin_manager::instance()->get_installed_plugins($this->type);
+        $versions = $this->pluginman->get_installed_plugins($this->type);
 
         if (isset($versions[$this->name])) {
             $this->versiondb = $versions[$this->name];
@@ -291,14 +299,15 @@ abstract class base {
      */
     public function init_is_standard() {
 
-        $standard = core_plugin_manager::standard_plugins_list($this->type);
+        $pluginman = $this->pluginman;
+        $standard = $pluginman::standard_plugins_list($this->type);
 
         if ($standard !== false) {
             $standard = array_flip($standard);
             if (isset($standard[$this->name])) {
                 $this->source = core_plugin_manager::PLUGIN_SOURCE_STANDARD;
             } else if (!is_null($this->versiondb) and is_null($this->versiondisk)
-                and core_plugin_manager::is_deleted_standard_plugin($this->type, $this->name)) {
+                and $pluginman::is_deleted_standard_plugin($this->type, $this->name)) {
                 $this->source = core_plugin_manager::PLUGIN_SOURCE_STANDARD; // To be deleted.
             } else {
                 $this->source = core_plugin_manager::PLUGIN_SOURCE_EXTENSION;
@@ -339,6 +348,8 @@ abstract class base {
      */
     public function get_status() {
 
+        $pluginman = $this->pluginman;
+
         if (is_null($this->versiondb) and is_null($this->versiondisk)) {
             return core_plugin_manager::PLUGIN_STATUS_NODB;
 
@@ -346,7 +357,7 @@ abstract class base {
             return core_plugin_manager::PLUGIN_STATUS_NEW;
 
         } else if (!is_null($this->versiondb) and is_null($this->versiondisk)) {
-            if (core_plugin_manager::is_deleted_standard_plugin($this->type, $this->name)) {
+            if ($pluginman::is_deleted_standard_plugin($this->type, $this->name)) {
                 return core_plugin_manager::PLUGIN_STATUS_DELETE;
             } else {
                 return core_plugin_manager::PLUGIN_STATUS_MISSING;
@@ -385,7 +396,7 @@ abstract class base {
             return false;
         }
 
-        $enabled = core_plugin_manager::instance()->get_enabled_plugins($this->type);
+        $enabled = $this->pluginman->get_enabled_plugins($this->type);
 
         if (!is_array($enabled)) {
             return null;
@@ -597,13 +608,4 @@ abstract class base {
             'return' => $return,
         ));
     }
-
-    /**
-     * Provides access to the core_plugin_manager singleton.
-     *
-     * @return core_plugin_manager
-     */
-    protected function get_plugin_manager() {
-        return core_plugin_manager::instance();
-    }
 }
diff --git a/lib/classes/plugininfo/format.php b/lib/classes/plugininfo/format.php
index d0d161d9a2b..5cbd7fb56b2 100644
--- a/lib/classes/plugininfo/format.php
+++ b/lib/classes/plugininfo/format.php
@@ -71,12 +71,14 @@ class format extends base {
      * @param string $type the name of the plugintype, eg. mod, auth or workshopform
      * @param string $typerootdir full path to the location of the plugin dir
      * @param string $typeclass the name of the actually called class
+     * @param core_plugin_manager $pluginman the plugin manager calling this method
      * @return array of plugintype classes, indexed by the plugin name
      */
-    public static function get_plugins($type, $typerootdir, $typeclass) {
+    public static function get_plugins($type, $typerootdir, $typeclass, $pluginman) {
         global $CFG;
-        $formats = parent::get_plugins($type, $typerootdir, $typeclass);
         require_once($CFG->dirroot.'/course/lib.php');
+
+        $formats = parent::get_plugins($type, $typerootdir, $typeclass, $pluginman);
         $order = get_sorted_course_formats();
         $sortedformats = array();
         foreach ($order as $formatname) {
@@ -137,7 +139,7 @@ class format extends base {
             return '';
         }
 
-        $defaultformat = $this->get_plugin_manager()->plugin_name('format_'.get_config('moodlecourse', 'format'));
+        $defaultformat = $this->pluginman->plugin_name('format_'.get_config('moodlecourse', 'format'));
         $message = get_string(
             'formatuninstallwithcourses', 'core_admin',
             (object)array('count' => $coursecount, 'format' => $this->displayname,
diff --git a/lib/classes/plugininfo/orphaned.php b/lib/classes/plugininfo/orphaned.php
index ec78d3931e1..09f12d6c681 100644
--- a/lib/classes/plugininfo/orphaned.php
+++ b/lib/classes/plugininfo/orphaned.php
@@ -64,12 +64,12 @@ class orphaned extends base {
      * @param string $type the name of the plugintype, eg. mod, auth or workshopform
      * @param string $typerootdir full path to the location of the plugin dir
      * @param string $typeclass the name of the actually called class
+     * @param core_plugin_manager $pluginman the plugin manager calling this method
      * @return array of plugintype classes, indexed by the plugin name
      */
-    public static function get_plugins($type, $typerootdir, $typeclass) {
+    public static function get_plugins($type, $typerootdir, $typeclass, $pluginman) {
         $return = array();
-        $manager = \core_plugin_manager::instance();
-        $plugins = $manager->get_installed_plugins($type);
+        $plugins = $pluginman->get_installed_plugins($type);
 
         foreach ($plugins as $name => $version) {
             $plugin              = new $typeclass();
@@ -79,6 +79,7 @@ class orphaned extends base {
             $plugin->rootdir     = null;
             $plugin->displayname = $name;
             $plugin->versiondb   = $version;
+            $plugin->pluginman   = $pluginman;
             $plugin->init_is_standard();
 
             $return[$name] = $plugin;
diff --git a/lib/tests/plugin_manager_test.php b/lib/tests/plugin_manager_test.php
index f9726e878cb..3926e3de607 100644
--- a/lib/tests/plugin_manager_test.php
+++ b/lib/tests/plugin_manager_test.php
@@ -124,6 +124,23 @@ class core_plugin_manager_testcase extends advanced_testcase {
         $this->assertSame($plugininfos2['mod']['forum'], $plugininfos4['mod']['forum']);
     }
 
+    public function test_plugininfo_back_reference_to_the_plugin_manager() {
+        $plugman1 = core_plugin_manager::instance();
+        $plugman2 = testable_core_plugin_manager::instance();
+
+        foreach ($plugman1->get_plugins() as $type => $infos) {
+            foreach ($infos as $info) {
+                $this->assertSame($info->pluginman, $plugman1);
+            }
+        }
+
+        foreach ($plugman2->get_plugins() as $type => $infos) {
+            foreach ($infos as $info) {
+                $this->assertSame($info->pluginman, $plugman2);
+            }
+        }
+    }
+
     public function test_get_plugins_of_type() {
         $plugininfos = core_plugin_manager::instance()->get_plugins();
         foreach ($plugininfos as $type => $infos) {