diff --git a/lib/adminlib.php b/lib/adminlib.php
index b7ba77ff91f..8af74d22b23 100644
--- a/lib/adminlib.php
+++ b/lib/adminlib.php
@@ -167,69 +167,15 @@ function uninstall_plugin($type, $name) {
 
     echo $OUTPUT->heading($pluginname);
 
+    // Custom plugin uninstall.
     $plugindirectory = core_component::get_plugin_directory($type, $name);
     $uninstalllib = $plugindirectory . '/db/uninstall.php';
     if (file_exists($uninstalllib)) {
         require_once($uninstalllib);
         $uninstallfunction = 'xmldb_' . $pluginname . '_uninstall';    // eg. 'xmldb_workshop_uninstall()'
         if (function_exists($uninstallfunction)) {
-            if (!$uninstallfunction()) {
-                echo $OUTPUT->notification('Encountered a problem running uninstall function for '. $pluginname);
-            }
-        }
-    }
-
-    if ($type === 'mod') {
-        // perform cleanup tasks specific for activity modules
-
-        if (!$module = $DB->get_record('modules', array('name' => $name))) {
-            print_error('moduledoesnotexist', 'error');
-        }
-
-        // delete all the relevant instances from all course sections
-        if ($coursemods = $DB->get_records('course_modules', array('module' => $module->id))) {
-            foreach ($coursemods as $coursemod) {
-                if (!delete_mod_from_section($coursemod->id, $coursemod->section)) {
-                    echo $OUTPUT->notification("Could not delete the $strpluginname with id = $coursemod->id from section $coursemod->section");
-                }
-            }
-        }
-
-        // Increment course.cacherev for courses that used this module.
-        // This will force cache rebuilding on the next request.
-        increment_revision_number('course', 'cacherev',
-                "id IN (SELECT DISTINCT course
-                                FROM {course_modules}
-                               WHERE module=?)",
-                array($module->id));
-
-        // delete all the course module records
-        $DB->delete_records('course_modules', array('module' => $module->id));
-
-        // delete module contexts
-        if ($coursemods) {
-            foreach ($coursemods as $coursemod) {
-                context_helper::delete_instance(CONTEXT_MODULE, $coursemod->id);
-            }
-        }
-
-        // delete the module entry itself
-        $DB->delete_records('modules', array('name' => $module->name));
-
-        // cleanup the gradebook
-        require_once($CFG->libdir.'/gradelib.php');
-        grade_uninstalled_module($module->name);
-
-        // Perform any custom uninstall tasks
-        if (file_exists($CFG->dirroot . '/mod/' . $module->name . '/lib.php')) {
-            require_once($CFG->dirroot . '/mod/' . $module->name . '/lib.php');
-            $uninstallfunction = $module->name . '_uninstall';
-            if (function_exists($uninstallfunction)) {
-                debugging("{$uninstallfunction}() has been deprecated. Use the plugin's db/uninstall.php instead", DEBUG_DEVELOPER);
-                if (!$uninstallfunction()) {
-                    echo $OUTPUT->notification('Encountered a problem running uninstall function for '. $module->name.'!');
-                }
-            }
+            // Do not verify result, let plugin complain if necessary.
+            $uninstallfunction();
         }
     }
 
diff --git a/lib/pluginlib.php b/lib/pluginlib.php
index a8afd85823f..8a8209279f7 100644
--- a/lib/pluginlib.php
+++ b/lib/pluginlib.php
@@ -3488,6 +3488,61 @@ class plugininfo_mod extends plugininfo_base {
 
         return '<p>'.get_string('uninstallextraconfirmmod', 'core_plugin', array('instances'=>$count, 'courses'=>$courses)).'</p>';
     }
+
+    /**
+     * Pre-uninstall hook.
+     *
+     * This is intended for disabling of plugin, some DB table purging, etc.
+     *
+     * NOTE: to be called from uninstall_plugin() only.
+     * @private
+     */
+    public function uninstall_cleanup() {
+        global $DB, $CFG;
+
+        if (!$module = $DB->get_record('modules', array('name' => $this->name))) {
+            parent::uninstall_cleanup();
+            return;
+        }
+
+        // Delete all the relevant instances from all course sections.
+        if ($coursemods = $DB->get_records('course_modules', array('module' => $module->id))) {
+            foreach ($coursemods as $coursemod) {
+                // Do not verify results, there is not much we can do anyway.
+                delete_mod_from_section($coursemod->id, $coursemod->section);
+            }
+        }
+
+        // Increment course.cacherev for courses that used this module.
+        // This will force cache rebuilding on the next request.
+        increment_revision_number('course', 'cacherev',
+            "id IN (SELECT DISTINCT course
+                      FROM {course_modules}
+                     WHERE module=?)",
+            array($module->id));
+
+        // Delete all the course module records.
+        $DB->delete_records('course_modules', array('module' => $module->id));
+
+        // Delete module contexts.
+        if ($coursemods) {
+            foreach ($coursemods as $coursemod) {
+                context_helper::delete_instance(CONTEXT_MODULE, $coursemod->id);
+            }
+        }
+
+        // Delete the module entry itself.
+        $DB->delete_records('modules', array('name' => $module->name));
+
+        // Cleanup the gradebook.
+        require_once($CFG->libdir.'/gradelib.php');
+        grade_uninstalled_module($module->name);
+
+        // Do not look for legacy $module->name . '_uninstall any more,
+        // they should have migrated to db/uninstall.php by now.
+
+        parent::uninstall_cleanup();
+    }
 }