diff --git a/main/admin/skill.php b/main/admin/skill.php
index e8851105ea..ce12f67e2c 100644
--- a/main/admin/skill.php
+++ b/main/admin/skill.php
@@ -1,7 +1,8 @@
 <?php
-
 /* For license terms, see /license.txt */
 
+use Chamilo\CoreBundle\Entity\Skill;
+
 /**
  * This script manages the skills, levels and profiles assignments.
  *
@@ -26,7 +27,7 @@ $id = isset($_GET['id']) ? $_GET['id'] : '';
 
 $item = null;
 if (!empty($id)) {
-    /** @var \Chamilo\CoreBundle\Entity\Skill $item */
+    /** @var Skill $item */
     $item = $em->getRepository('ChamiloCoreBundle:Skill')->find($id);
     if (!$item) {
         api_not_allowed();
diff --git a/main/admin/sub_language_ajax.inc.php b/main/admin/sub_language_ajax.inc.php
index 79d4442a69..cc0fc069cc 100755
--- a/main/admin/sub_language_ajax.inc.php
+++ b/main/admin/sub_language_ajax.inc.php
@@ -1,5 +1,8 @@
 <?php
 /* For licensing terms, see /license.txt */
+
+use \Chamilo\CoreBundle\Entity\ExtraField;
+
 /**
  * Sub language AJAX script to update variables
  * @package chamilo.admin.sub_language
@@ -53,13 +56,13 @@ if (isset($new_language) && isset($language_variable) && isset($file_id)) {
         $redirectUrl = api_get_path(WEB_CODE_PATH) . 'admin/extra_fields.php?type=';
 
         switch ($_REQUEST['extra_field_type']) {
-            case \Chamilo\CoreBundle\Entity\ExtraField::USER_FIELD_TYPE:
+            case ExtraField::USER_FIELD_TYPE:
                 $redirectUrl .= 'user';
                 break;
-            case \Chamilo\CoreBundle\Entity\ExtraField::COURSE_FIELD_TYPE:
+            case ExtraField::COURSE_FIELD_TYPE:
                 $redirectUrl .= 'course';
                 break;
-            case \Chamilo\CoreBundle\Entity\ExtraField::SESSION_FIELD_TYPE:
+            case ExtraField::SESSION_FIELD_TYPE:
                 $redirectUrl .= 'session';
                 break;
         }
diff --git a/main/extrafield/translate.php b/main/extrafield/translate.php
index 4abddddf52..7ccbb55047 100644
--- a/main/extrafield/translate.php
+++ b/main/extrafield/translate.php
@@ -1,6 +1,8 @@
 <?php
 /* For licensing terms, see /license.txt */
 
+use \Chamilo\CoreBundle\Entity\ExtraField;
+
 $cidReset = true;
 
 require_once '../inc/global.inc.php';
@@ -73,19 +75,19 @@ $form->freeze(['variable_language', 'original_name']);
 $interbreadcrumb[] = ['url' => api_get_path(WEB_CODE_PATH) . 'admin', 'name' => get_lang('Administration')];
 
 switch ($extraField->getExtraFieldType()) {
-    case \Chamilo\CoreBundle\Entity\ExtraField::USER_FIELD_TYPE:
+    case ExtraField::USER_FIELD_TYPE:
         $interbreadcrumb[] = [
             'url' => api_get_path(WEB_CODE_PATH) . 'admin/extra_fields.php?type=user',
             'name' => get_lang('UserFields')
         ];
         break;
-    case \Chamilo\CoreBundle\Entity\ExtraField::COURSE_FIELD_TYPE:
+    case ExtraField::COURSE_FIELD_TYPE:
         $interbreadcrumb[] = [
             'url' => api_get_path(WEB_CODE_PATH) . 'admin/extra_fields.php?type=course',
             'name' => get_lang('CourseFields')
         ];
         break;
-    case \Chamilo\CoreBundle\Entity\ExtraField::SESSION_FIELD_TYPE:
+    case ExtraField::SESSION_FIELD_TYPE:
         $interbreadcrumb[] = [
             'url' => api_get_path(WEB_CODE_PATH) . 'admin/extra_fields.php?type=session',
             'name' => get_lang('SessionFields')
diff --git a/main/inc/lib/display.lib.php b/main/inc/lib/display.lib.php
index d24f04f172..1883bb90e0 100755
--- a/main/inc/lib/display.lib.php
+++ b/main/inc/lib/display.lib.php
@@ -2,6 +2,7 @@
 /* For licensing terms, see /license.txt */
 
 use ChamiloSession as Session;
+use Chamilo\CoreBundle\Entity\ExtraField;
 
 /**
  * Class Display
@@ -1639,7 +1640,7 @@ class Display
             $entityManager = Database::getManager();
             $fieldValuesRepo = $entityManager->getRepository('ChamiloCoreBundle:ExtraFieldValues');
             $extraFieldValues = $fieldValuesRepo->getVisibleValues(
-                Chamilo\CoreBundle\Entity\ExtraField::SESSION_FIELD_TYPE,
+                ExtraField::SESSION_FIELD_TYPE,
                 $session_id
             );
 
diff --git a/main/inc/lib/extra_field_value.lib.php b/main/inc/lib/extra_field_value.lib.php
index 41e935e3f2..9a5ef8a03b 100755
--- a/main/inc/lib/extra_field_value.lib.php
+++ b/main/inc/lib/extra_field_value.lib.php
@@ -3,6 +3,7 @@
 
 use Chamilo\CoreBundle\Entity\ExtraField as EntityExtraField;
 use Chamilo\CoreBundle\Entity\Tag;
+use Chamilo\CoreBundle\Entity\ExtraFieldRelTag;
 
 /**
  * Class ExtraFieldValue
@@ -189,7 +190,7 @@ class ExtraFieldValue extends Model
                     $em->flush();
 
                     foreach ($tags as $tag) {
-                        $fieldRelTag = new Chamilo\CoreBundle\Entity\ExtraFieldRelTag();
+                        $fieldRelTag = new ExtraFieldRelTag();
                         $fieldRelTag->setFieldId($extraFieldInfo['id']);
                         $fieldRelTag->setItemId($params['item_id']);
                         $fieldRelTag->setTagId($tag->getId());
@@ -709,7 +710,7 @@ class ExtraFieldValue extends Model
                     sf.extra_field_type = $extraFieldType
                 ORDER BY item_id
                 ";
-        
+
         if ($last) {
             // If we want the last element instead of the first
             // This is useful in special cases where there might
diff --git a/main/inc/lib/sessionmanager.lib.php b/main/inc/lib/sessionmanager.lib.php
index aec0e10a3b..7e72fc0a7f 100755
--- a/main/inc/lib/sessionmanager.lib.php
+++ b/main/inc/lib/sessionmanager.lib.php
@@ -2,6 +2,7 @@
 /* For licensing terms, see /license.txt */
 
 use Chamilo\CoreBundle\Entity\SessionRelCourseRelUser;
+use Chamilo\CoreBundle\Entity\ExtraField;
 
 /**
  * Class SessionManager
@@ -6105,7 +6106,7 @@ class SessionManager
             foreach ($extraFields as $field) {
                 $fieldsArray[] = Database::escape_string($field);
             }
-            $extraFieldType = \Chamilo\CoreBundle\Entity\ExtraField::SESSION_FIELD_TYPE;
+            $extraFieldType = ExtraField::SESSION_FIELD_TYPE;
             if (isset ($publicationDate)) {
                 $publicationDateString = $publicationDate->format('Y-m-d H:i:s');
                 $wherePublication = " AND id NOT IN (
@@ -6266,7 +6267,7 @@ class SessionManager
                 )
             );
 
-            $extraFieldType = \Chamilo\CoreBundle\Entity\ExtraField::SESSION_FIELD_TYPE;
+            $extraFieldType = ExtraField::SESSION_FIELD_TYPE;
 
             // Check if session list query had result
             if (!empty($sessionList)) {
@@ -6411,7 +6412,7 @@ class SessionManager
         $sfvTable = Database::get_main_table(TABLE_EXTRA_FIELD_VALUES);
 
         $term = Database::escape_string($term);
-        $extraFieldType = \Chamilo\CoreBundle\Entity\ExtraField::SESSION_FIELD_TYPE;
+        $extraFieldType = ExtraField::SESSION_FIELD_TYPE;
         if (is_array($extraFieldsToInclude) && count($extraFieldsToInclude) > 0) {
             $resultData = Database::select('*', $sTable, array(
                 'where' => array(
diff --git a/main/user/subscribe_user.php b/main/user/subscribe_user.php
index 9def3d1c4b..5440ebc952 100755
--- a/main/user/subscribe_user.php
+++ b/main/user/subscribe_user.php
@@ -1,6 +1,8 @@
 <?php
 /* For licensing terms, see /license.txt*/
 
+use Chamilo\CoreBundle\Entity\ExtraField;
+
 /**
 * This script allows teachers to subscribe existing users
 * to their course.
@@ -840,7 +842,7 @@ function search_additional_profile_fields($keyword)
 		$profiling_field_options_exact_values_sql .= " OR (field_id = '".$profilingvalue['field_id']."' AND value='".$profilingvalue['option_value']."') ";
 	}
 
-    $extraFieldType = \Chamilo\CoreBundle\Entity\ExtraField::USER_FIELD_TYPE;
+    $extraFieldType = ExtraField::USER_FIELD_TYPE;
 
 	// getting all the user ids of the users who have chosen on of the predefined fields that contain the keyword
 	// or all the users who have entered the keyword in a free-form field