diff --git a/server_files/controllers/rejoindre_equipe.php b/server_files/controllers/rejoindre_equipe.php
index 494ab1c..dadcf35 100644
--- a/server_files/controllers/rejoindre_equipe.php
+++ b/server_files/controllers/rejoindre_equipe.php
@@ -3,48 +3,64 @@
 if (isset($_SESSION["team"]) || !isset($_SESSION["user"]) || ($_SESSION["role"] != Role::PARTICIPANT && $_SESSION["role"] != Role::ENCADRANT))
 	require_once "server_files/403.php";
 
+$has_error = false;
+$error_message = null;
+
 if (isset($_POST["submitted"])) {
-	$error_message = joinTeam();
+	$join_team = new JoinTeam($_POST);
+	try {
+		$join_team->makeVerifications();
+		$join_team->joinTeam();
+	} catch (AssertionError $e) {
+		$has_error = true;
+		$error_message = $e->getMessage();
+	}
 }
 
-function joinTeam() {
-	global $access_code;
-	
-	$access_code = htmlspecialchars($_POST["access_code"]);
-	
-	if (!isset($access_code) || strlen($access_code) != 6)
-		return "Le code d'accès doit comporter 6 caractères.";
+class JoinTeam
+{
+	private $access_code;
+	private $team;
+	private $min_null_index;
 
-	/** @var User $user */
-	$user = $_SESSION["user"];
-	$team = Team::fromAccessCode($access_code);
-	if ($team === null)
-		return "Ce code d'accès est invalide.";
-
-	if ($team->getValidationStatus() != ValidationStatus::NOT_READY)
-	    return "Cette équipe est déjà en cours de validation ou validée, vous ne pouvez pas la rejoindre.";
-	
-	for ($i = 1; $i <= $_SESSION["role"] == Role::PARTICIPANT ? 6 : 2; ++$i) {
-		if (($_SESSION["role"] == Role::PARTICIPANT ? $team->getParticipants()[$i - 1] : $team->getEncadrants()[$i - 1]) == NULL)
-			break;
+	public function __construct($data)
+	{
+		$this->access_code = strtolower(htmlspecialchars($data["access_code"]));
+		$this->team = Team::fromAccessCode($this->access_code);
 	}
-	
-	if ($_SESSION["role"] == Role::PARTICIPANT && $i == 7 || $_SESSION["role"] == Role::ENCADRANT && $i == 3)
-		return "Il n'y a plus de place pour vous dans l'équipe.";
 
-	$user->setTeamId($team->getId());
+	public function makeVerifications()
+	{
+		ensure(preg_match("#[a-z0-9]{6}#", $this->access_code), "Le code d'accès doit comporter 6 caractères alphanumériques.");
+		ensure($this->team != null, "Ce code d'accès est invalide.");
+		ensure($this->team->getValidationStatus() == ValidationStatus::NOT_READY, "Cette équipe est déjà validée ou en cours de validation, vous ne pouvez pas la rejoindre.");
 
-    if ($_SESSION["role"] == Role::ENCADRANT)
-    	$team->setEncadrant($i, $user->getId());
-    else
-    	$team->setParticipant($i, $user->getId());
+		for ($i = 1; $i <= $_SESSION["role"] == Role::PARTICIPANT ? 6 : 2; ++$i) {
+			if (($_SESSION["role"] == Role::PARTICIPANT ? $this->team->getParticipants()[$i - 1] : $this->team->getEncadrants()[$i - 1]) == NULL)
+				break;
+		}
 
-    $_SESSION["team"] = $team;
-    $tournament = $_SESSION["tournament"] = Tournament::fromId($team->getTournamentId());
+		$this->min_null_index = $i;
 
-	Mailer::sendJoinTeamMail($user, $team, $tournament);
-	
-	return false;
+		ensure($_SESSION["role"] == Role::PARTICIPANT && $this->min_null_index <= 6 || $_SESSION["role"] == Role::ENCADRANT && $this->min_null_index <= 2, "Il n'y a plus de place pour vous dans l'équipe.");
+	}
+
+	public function joinTeam()
+	{
+		$user = $_SESSION["user"];
+
+		$user->setTeamId($this->team->getId());
+
+		if ($_SESSION["role"] == Role::ENCADRANT)
+			$this->team->setEncadrant($this->min_null_index, $user->getId());
+		else
+			$this->team->setParticipant($this->min_null_index, $user->getId());
+
+		$_SESSION["team"] = $this->team;
+		$tournament = $_SESSION["tournament"] = Tournament::fromId($this->team->getTournamentId());
+
+		Mailer::sendJoinTeamMail($user, $this->team, $tournament);
+	}
 }
 
 require_once "server_files/views/rejoindre_equipe.php";
diff --git a/server_files/views/equipe.php b/server_files/views/equipe.php
index 4f0d332..af1315c 100644
--- a/server_files/views/equipe.php
+++ b/server_files/views/equipe.php
@@ -7,7 +7,7 @@
     Tournoi : <a href="<?= $URL_BASE . "/tournoi/" . $tournament->getName() ?>"><?= $tournament->getName() ?></a><br/>
 <?php
 for ($i = 1; $i <= 2; ++$i) {
-	if ($team->getEncadrants()[$i] == NULL)
+	if ($team->getEncadrants()[$i - 1] == NULL)
 		continue;
 	$encadrant = User::fromId($team->getEncadrants()[$i - 1]);
 	$id = $encadrant->getId();
diff --git a/server_files/views/rejoindre_equipe.php b/server_files/views/rejoindre_equipe.php
index ce75669..de638ee 100644
--- a/server_files/views/rejoindre_equipe.php
+++ b/server_files/views/rejoindre_equipe.php
@@ -1,11 +1,11 @@
 <?php
 require_once "header.php" ;
 
-if (isset($error_message) && $error_message === false) { ?>
+if (isset($join_team) && !$has_error) { ?>
 	Vous avez bien rejoint l'équipe <?= $_SESSION["team"]->getName() ?> !
 <?php } else { ?>
 
-	<?php if (isset($error_message) && $error_message) echo "<h2>Erreur : " . $error_message . "</h2>"; ?>
+	<?php if ($has_error) echo "<h2>Erreur : " . $error_message . "</h2>"; ?>
 
 	<form method="POST">
 		<input type="hidden" name="submitted" value="true" />