diff --git a/lib/adminlib.php b/lib/adminlib.php
index 48c9099cd9c..d26e0f90761 100644
--- a/lib/adminlib.php
+++ b/lib/adminlib.php
@@ -269,6 +269,10 @@ function uninstall_plugin($type, $name) {
 
     // perform clean-up task common for all the plugin/subplugin types
 
+    //delete the web service functions and pre-built services
+    require_once($CFG->dirroot.'/lib/externallib.php');
+    external_delete_descriptions($component);
+
     // delete calendar events
     $DB->delete_records('event', array('modulename' => $pluginname));
 
diff --git a/lib/externallib.php b/lib/externallib.php
index 88753071bad..2cb1118d960 100644
--- a/lib/externallib.php
+++ b/lib/externallib.php
@@ -487,4 +487,24 @@ function external_create_service_token($servicename, $context){
     global $USER, $DB;
     $service = $DB->get_record('external_services', array('name'=>$servicename), '*', MUST_EXIST);
     return external_generate_token(EXTERNAL_TOKEN_EMBEDDED, $service, $USER->id, $context, 0);
+}
+
+/**
+ * Delete all pre-built services (+ related tokens) and external functions information defined in the specified component.
+ *
+ * @param string $component name of component (moodle, mod_assignment, etc.)
+ */
+function external_delete_descriptions($component) {
+    global $DB;
+
+    $params = array($component);
+
+    $DB->delete_records_select('external_tokens',
+            "externalserviceid IN (SELECT id FROM {external_services} WHERE component = ?)", $params);
+    $DB->delete_records_select('external_services_users',
+            "externalserviceid IN (SELECT id FROM {external_services} WHERE component = ?)", $params);
+    $DB->delete_records_select('external_services_functions',
+            "functionname IN (SELECT name FROM {external_functions} WHERE component = ?)", $params);
+    $DB->delete_records('external_services', array('component'=>$component));
+    $DB->delete_records('external_functions', array('component'=>$component));
 }
\ No newline at end of file
diff --git a/lib/upgradelib.php b/lib/upgradelib.php
index 6db42165dc7..583176f1fc9 100644
--- a/lib/upgradelib.php
+++ b/lib/upgradelib.php
@@ -869,11 +869,12 @@ function log_update_descriptions($component) {
  * @return void
  */
 function external_update_descriptions($component) {
-    global $DB;
+    global $DB, $CFG;
 
     $defpath = get_component_directory($component).'/db/services.php';
 
     if (!file_exists($defpath)) {
+        require_once($CFG->dirroot.'/lib/externallib.php');
         external_delete_descriptions($component);
         return;
     }
@@ -937,6 +938,7 @@ function external_update_descriptions($component) {
     $dbservices = $DB->get_records('external_services', array('component'=>$component));
     foreach ($dbservices as $dbservice) {
         if (empty($services[$dbservice->name])) {
+            $DB->delete_records('external_tokens', array('externalserviceid'=>$dbservice->id));
             $DB->delete_records('external_services_functions', array('externalserviceid'=>$dbservice->id));
             $DB->delete_records('external_services_users', array('externalserviceid'=>$dbservice->id));
             $DB->delete_records('external_services', array('id'=>$dbservice->id));
@@ -1030,22 +1032,6 @@ function external_update_descriptions($component) {
     }
 }
 
-/**
- * Delete all service and external functions information defined in the specified component.
- * @param string $component name of component (moodle, mod_assignment, etc.)
- * @return void
- */
-function external_delete_descriptions($component) {
-    global $DB;
-
-    $params = array($component);
-
-    $DB->delete_records_select('external_services_users', "externalserviceid IN (SELECT id FROM {external_services} WHERE component = ?)", $params);
-    $DB->delete_records_select('external_services_functions', "externalserviceid IN (SELECT id FROM {external_services} WHERE component = ?)", $params);
-    $DB->delete_records('external_services', array('component'=>$component));
-    $DB->delete_records('external_functions', array('component'=>$component));
-}
-
 /**
  * upgrade logging functions
  */