diff --git a/src/CoreBundle/Entity/Promotion.php b/src/CoreBundle/Entity/Promotion.php
index fad3ad595e..666201645c 100644
--- a/src/CoreBundle/Entity/Promotion.php
+++ b/src/CoreBundle/Entity/Promotion.php
@@ -6,6 +6,7 @@ declare(strict_types=1);
 
 namespace Chamilo\CoreBundle\Entity;
 
+use Doctrine\Common\Collections\Collection;
 use Doctrine\ORM\Mapping as ORM;
 use Gedmo\Timestampable\Traits\TimestampableEntity;
 use Symfony\Component\Validator\Constraints as Assert;
@@ -47,6 +48,15 @@ class Promotion
      */
     protected Career $career;
 
+    /**
+     * @var Collection|Session[]
+     *
+     * @ORM\OneToMany(
+     *     targetEntity="Chamilo\CoreBundle\Entity\Session", mappedBy="promotion", cascade={"persist"}
+     * )
+     */
+    protected Collection $sessions;
+
     /**
      * @ORM\Column(name="status", type="integer", nullable=false)
      */
@@ -67,12 +77,7 @@ class Promotion
         return $this->id;
     }
 
-    /**
-     * Set name.
-     *
-     * @return Promotion
-     */
-    public function setName(string $name)
+    public function setName(string $name): self
     {
         $this->name = $name;
 
diff --git a/src/CoreBundle/Entity/Session.php b/src/CoreBundle/Entity/Session.php
index 7e99e035ee..d1d8eebc43 100644
--- a/src/CoreBundle/Entity/Session.php
+++ b/src/CoreBundle/Entity/Session.php
@@ -187,6 +187,15 @@ class Session
      */
     protected User $sessionAdmin;
 
+    /**
+     * @Assert\NotBlank
+     * @Groups({"session:read", "session:write"})
+     *
+     * @ORM\ManyToOne(targetEntity="User", inversedBy="sessionsAsGeneralCoach")
+     * @ORM\JoinColumn(name="id_coach", referencedColumnName="id")
+     */
+    protected User $generalCoach;
+
     /**
      * @Groups({"session:read"})
      * @ORM\Column(name="visibility", type="integer")
@@ -194,9 +203,10 @@ class Session
     protected int $visibility;
 
     /**
-     * @ORM\Column(name="promotion_id", type="integer", nullable=true, unique=false)
+     * @ORM\ManyToOne(targetEntity="Chamilo\CoreBundle\Entity\Promotion", inversedBy="sessions", cascade={"persist"})
+     * @ORM\JoinColumn(name="promotion_id", referencedColumnName="id", onDelete="CASCADE")
      */
-    protected ?int $promotionId = null;
+    protected ?Promotion $promotion;
 
     /**
      * @Groups({"session:read"})
@@ -242,15 +252,6 @@ class Session
      */
     protected int $status;
 
-    /**
-     * @Assert\NotBlank
-     * @Groups({"session:read", "session:write"})
-     *
-     * @ORM\ManyToOne(targetEntity="User", inversedBy="sessionsAsGeneralCoach")
-     * @ORM\JoinColumn(name="id_coach", referencedColumnName="id")
-     */
-    protected User $generalCoach;
-
     /**
      * @Groups({"session:read", "session:write"})
      * @ORM\ManyToOne(targetEntity="SessionCategory", inversedBy="session")
@@ -658,26 +659,16 @@ class Session
         return $this->visibility;
     }
 
-    /**
-     * Set promotionId.
-     *
-     * @return Session
-     */
-    public function setPromotionId(int $promotionId)
+    public function getPromotion(): ?Promotion
     {
-        $this->promotionId = $promotionId;
-
-        return $this;
+        return $this->promotion;
     }
 
-    /**
-     * Get promotionId.
-     *
-     * @return int
-     */
-    public function getPromotionId()
+    public function setPromotion(?Promotion $promotion): self
     {
-        return $this->promotionId;
+        $this->promotion = $promotion;
+
+        return $this;
     }
 
     /**
diff --git a/src/CoreBundle/Entity/SessionRelUser.php b/src/CoreBundle/Entity/SessionRelUser.php
index e16fa4e5bb..a6eab69886 100644
--- a/src/CoreBundle/Entity/SessionRelUser.php
+++ b/src/CoreBundle/Entity/SessionRelUser.php
@@ -48,7 +48,7 @@ class SessionRelUser
     protected Session $session;
 
     /**
-     * @ORM\ManyToOne(targetEntity="User", inversedBy="sessions", cascade={"persist"})
+     * @ORM\ManyToOne(targetEntity="User", inversedBy="sessionsRelUser", cascade={"persist"})
      * @ORM\JoinColumn(name="user_id", referencedColumnName="id")
      */
     protected User $user;
diff --git a/src/CoreBundle/Migrations/Schema/V200/Version20190210182615.php b/src/CoreBundle/Migrations/Schema/V200/Version20190210182615.php
index 3a3582c39f..3c09fd1088 100644
--- a/src/CoreBundle/Migrations/Schema/V200/Version20190210182615.php
+++ b/src/CoreBundle/Migrations/Schema/V200/Version20190210182615.php
@@ -23,6 +23,12 @@ class Version20190210182615 extends AbstractMigrationChamilo
             $this->addSql('ALTER TABLE session CHANGE position position INT DEFAULT 0 NOT NULL');
         }
 
+        $this->addSql('UPDATE session SET promotion_id = NULL WHERE promotion_id = 0');
+        if (false === $table->hasForeignKey('FK_D044D5D4139DF194')) {
+            $this->addSql('ALTER TABLE session ADD CONSTRAINT FK_D044D5D4139DF194 FOREIGN KEY (promotion_id) REFERENCES promotion (id) ON DELETE CASCADE');
+            $this->addSql('CREATE INDEX IDX_D044D5D4139DF194 ON session (promotion_id);');
+        }
+
         if (false === $table->hasColumn('status')) {
             $this->addSql('ALTER TABLE session ADD COLUMN status INT NOT NULL');
         }