diff --git a/ecs.yaml b/ecs.yaml
index 915c795403..659a2819b9 100644
--- a/ecs.yaml
+++ b/ecs.yaml
@@ -9,3 +9,4 @@ parameters:
     sets:
         - 'clean-code'
         - 'symfony'
+        - 'symfony-risky'
diff --git a/src/CoreBundle/Component/Editor/Editor.php b/src/CoreBundle/Component/Editor/Editor.php
index 50914d2966..3fa9603677 100644
--- a/src/CoreBundle/Component/Editor/Editor.php
+++ b/src/CoreBundle/Component/Editor/Editor.php
@@ -203,7 +203,7 @@ class Editor
                 // Arrays in JSON can't be associative. If the array is empty or if it
                 // has sequential whole number keys starting with 0, it's not associative
                 // so we can go ahead and convert it as an array.
-                if (empty($var) || array_keys($var) === range(0, sizeof($var) - 1)) {
+                if (empty($var) || array_keys($var) === range(0, count($var) - 1)) {
                     $output = [];
                     foreach ($var as $v) {
                         $output[] = $this->toJavascript($v);
@@ -216,7 +216,7 @@ class Editor
                 // Otherwise, fall through to convert the array as an object.
                 $output = [];
                 foreach ($var as $k => $v) {
-                    $output[] = $this->toJavascript(strval($k)).': '.$this->toJavascript($v);
+                    $output[] = $this->toJavascript((string) $k).': '.$this->toJavascript($v);
                 }
 
                 return '{ '.implode(', ', $output).' }';
diff --git a/src/CoreBundle/Component/Utils/ChamiloApi.php b/src/CoreBundle/Component/Utils/ChamiloApi.php
index 419de150a1..e2ad46e1bb 100644
--- a/src/CoreBundle/Component/Utils/ChamiloApi.php
+++ b/src/CoreBundle/Component/Utils/ChamiloApi.php
@@ -312,7 +312,7 @@ class ChamiloApi
             foreach ($palette as $index => $color) {
                 $components = preg_split('/,/', trim($color));
                 $components[3] = round($components[3] / 100, 1);
-                $palette[$index] = join(',', $components);
+                $palette[$index] = implode(',', $components);
             }
         }
         if ($wrapInRGBA) {
diff --git a/src/CoreBundle/Controller/CourseController.php b/src/CoreBundle/Controller/CourseController.php
index bd09f10f95..e04d81b3c0 100644
--- a/src/CoreBundle/Controller/CourseController.php
+++ b/src/CoreBundle/Controller/CourseController.php
@@ -99,7 +99,7 @@ class CourseController extends AbstractController
 
         $courseTags = [];
 
-        if (!is_null($tagField)) {
+        if (null !== $tagField) {
             $courseTags = $fieldTagsRepo->getTags($tagField, $courseId);
         }
 
diff --git a/src/CoreBundle/Controller/SessionController.php b/src/CoreBundle/Controller/SessionController.php
index 1285fa54bd..a46c5f4486 100644
--- a/src/CoreBundle/Controller/SessionController.php
+++ b/src/CoreBundle/Controller/SessionController.php
@@ -67,7 +67,7 @@ class SessionController extends AbstractController
             $sessionCourse = $sessionRelCourse->getCourse();
             $courseTags = [];
 
-            if (!is_null($tagField)) {
+            if (null !== $tagField) {
                 $courseTags = $fieldTagsRepo->getTags($tagField, $sessionCourse->getId());
             }
 
diff --git a/src/CoreBundle/Entity/Course.php b/src/CoreBundle/Entity/Course.php
index 38ac4381b5..c9d166e85c 100644
--- a/src/CoreBundle/Entity/Course.php
+++ b/src/CoreBundle/Entity/Course.php
@@ -913,7 +913,7 @@ class Course extends AbstractResource implements ResourceInterface
      */
     public function setDiskQuota($diskQuota)
     {
-        $this->diskQuota = intval($diskQuota);
+        $this->diskQuota = (int) $diskQuota;
 
         return $this;
     }
diff --git a/src/CoreBundle/Entity/Session.php b/src/CoreBundle/Entity/Session.php
index 0d8ea91adb..75c2e3cf2d 100644
--- a/src/CoreBundle/Entity/Session.php
+++ b/src/CoreBundle/Entity/Session.php
@@ -552,7 +552,7 @@ class Session
             Criteria::expr()->eq('user', $user)
         );
 
-        if (!is_null($status)) {
+        if (null !== $status) {
             $criteria->andWhere(
                 Criteria::expr()->eq('status', $status)
             );
diff --git a/src/CoreBundle/Entity/SettingsCurrent.php b/src/CoreBundle/Entity/SettingsCurrent.php
index 0d4925e5b4..d2eaea729f 100644
--- a/src/CoreBundle/Entity/SettingsCurrent.php
+++ b/src/CoreBundle/Entity/SettingsCurrent.php
@@ -374,7 +374,7 @@ class SettingsCurrent
      */
     public function setAccessUrlLocked($accessUrlLocked)
     {
-        $this->accessUrlLocked = intval($accessUrlLocked);
+        $this->accessUrlLocked = (int) $accessUrlLocked;
 
         return $this;
     }
diff --git a/src/CoreBundle/Migrations/Schema/V110/Version20151214170800.php b/src/CoreBundle/Migrations/Schema/V110/Version20151214170800.php
index 1c6d05a204..1c22364b61 100644
--- a/src/CoreBundle/Migrations/Schema/V110/Version20151214170800.php
+++ b/src/CoreBundle/Migrations/Schema/V110/Version20151214170800.php
@@ -56,10 +56,10 @@ class Version20151214170800 extends AbstractMigrationChamilo
             switch ($answer['hotspot_type']) {
                 case 'square':
                     $oldCenter = explode(';', $oldPairedString[0]);
-                    $oldCenterX = intval($oldCenter[0]);
-                    $oldCenterY = intval($oldCenter[1]);
-                    $oldWidth = intval($oldPairedString[1]);
-                    $oldHeight = intval($oldPairedString[2]);
+                    $oldCenterX = (int) ($oldCenter[0]);
+                    $oldCenterY = (int) ($oldCenter[1]);
+                    $oldWidth = (int) ($oldPairedString[1]);
+                    $oldHeight = (int) ($oldPairedString[2]);
 
                     $newX = floor(($oldCenterX - $oldWidth / 2) * $widthRatio) + ceil($widthRatio);
                     $newY = floor(($oldCenterY - $oldHeight / 2) * $heightRatio) + ceil($heightRatio);
@@ -73,10 +73,10 @@ class Version20151214170800 extends AbstractMigrationChamilo
                     break;
                 case 'circle':
                     $oldCenter = explode(';', $oldPairedString[0]);
-                    $oldCenterX = intval($oldCenter[0]);
-                    $oldCenterY = intval($oldCenter[1]);
-                    $oldRadiusX = intval($oldPairedString[1]) / 2;
-                    $oldRadiusY = intval($oldPairedString[2]) / 2;
+                    $oldCenterX = (int) ($oldCenter[0]);
+                    $oldCenterY = (int) ($oldCenter[1]);
+                    $oldRadiusX = (int) ($oldPairedString[1]) / 2;
+                    $oldRadiusY = (int) ($oldPairedString[2]) / 2;
 
                     $newCenterX = floor($oldCenterX * $widthRatio) + ceil($widthRatio);
                     $newCenterY = floor($oldCenterY * $heightRatio) + ceil($heightRatio);
@@ -94,8 +94,8 @@ class Version20151214170800 extends AbstractMigrationChamilo
                     $paired = [];
                     foreach ($oldPairedString as $pairString) {
                         $pair = explode(';', $pairString);
-                        $x = isset($pair[0]) ? intval($pair[0]) : 0;
-                        $y = isset($pair[1]) ? intval($pair[1]) : 0;
+                        $x = isset($pair[0]) ? (int) ($pair[0]) : 0;
+                        $y = isset($pair[1]) ? (int) ($pair[1]) : 0;
 
                         $paired[] = [$x, $y];
                     }
diff --git a/src/CoreBundle/Repository/ExtraFieldRelTagRepository.php b/src/CoreBundle/Repository/ExtraFieldRelTagRepository.php
index 0ddd01ad91..88c52e2de6 100644
--- a/src/CoreBundle/Repository/ExtraFieldRelTagRepository.php
+++ b/src/CoreBundle/Repository/ExtraFieldRelTagRepository.php
@@ -47,7 +47,7 @@ class ExtraFieldRelTagRepository extends ServiceEntityRepository
             )
             ->where(
                 $queryBuilder->expr()->andX(
-                    $queryBuilder->expr()->eq('ft.itemId', intval($itemId)),
+                    $queryBuilder->expr()->eq('ft.itemId', (int) $itemId),
                     $queryBuilder->expr()->eq('ft.fieldId', $extraField->getId())
                 )
             );
diff --git a/src/CoreBundle/Repository/ExtraFieldValuesRepository.php b/src/CoreBundle/Repository/ExtraFieldValuesRepository.php
index 4de7260349..94b8338084 100644
--- a/src/CoreBundle/Repository/ExtraFieldValuesRepository.php
+++ b/src/CoreBundle/Repository/ExtraFieldValuesRepository.php
@@ -46,8 +46,8 @@ class ExtraFieldValuesRepository extends ServiceEntityRepository
             )
             ->where(
                 $queryBuilder->expr()->andX(
-                    $queryBuilder->expr()->eq('f.extraFieldType', intval($extraFieldType)),
-                    $queryBuilder->expr()->eq('fv.itemId', intval($itemId)),
+                    $queryBuilder->expr()->eq('f.extraFieldType', (int) $extraFieldType),
+                    $queryBuilder->expr()->eq('fv.itemId', (int) $itemId),
                     $queryBuilder->expr()->eq('f.visibleToSelf', true)
                 )
             )