diff --git a/modules/VelonimoCard.php b/modules/VelonimoCard.php
index f0b8efe..1885207 100644
--- a/modules/VelonimoCard.php
+++ b/modules/VelonimoCard.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 class VelonimoCard
 {
     private int $bgaId;
diff --git a/modules/VelonimoPlayer.php b/modules/VelonimoPlayer.php
index a0057f8..02b243a 100644
--- a/modules/VelonimoPlayer.php
+++ b/modules/VelonimoPlayer.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 class VelonimoPlayer
 {
     private const ROUNDS_RANKING_SERIALIZED_KEY_VALUE_SEPARATOR = '=';
@@ -43,7 +45,13 @@ public static function deserializeRoundsRanking(string $serialized): array
     {
         /** @var string[] $rounds */
         $rounds = explode(self::ROUNDS_RANKING_SERIALIZED_ROUNDS_SEPARATOR, $serialized);
-        if (!$rounds) {
+        if (
+            !$rounds
+            || (
+                count($rounds) === 1
+                && $rounds[0] === ''
+            )
+        ) {
             return [];
         }
 
diff --git a/modules/constants.inc.php b/modules/constants.inc.php
index 8c703e6..b01f827 100644
--- a/modules/constants.inc.php
+++ b/modules/constants.inc.php
@@ -1,5 +1,8 @@
 <?php
-/*
+
+declare(strict_types=1);
+
+/**
  * Velonimo constants
  */
 
diff --git a/velonimo.game.php b/velonimo.game.php
index b5143a4..db687fb 100644
--- a/velonimo.game.php
+++ b/velonimo.game.php
@@ -16,6 +16,7 @@
   *
   */
 
+declare(strict_types=1);
 
 require_once(APP_GAMEMODULE_PATH.'module/table/table.game.php');
 require_once('modules/constants.inc.php');
@@ -436,6 +437,8 @@ function stStartRound()
         // if there is a loser, he plays first during this round
         if ($currentLoser = $this->getCurrentLoser($players)) {
             $this->gamestate->changeActivePlayer($currentLoser->getId());
+        } else {
+            self::activeNextPlayer();
         }
 
         $this->gamestate->nextState('firstPlayerTurn');
@@ -604,9 +607,9 @@ function upgradeTableDb($from_version)
     private function fromBgaCardsToVelonimoCards(array $bgaCards): array {
         return array_map(
             fn (array $card) => new VelonimoCard(
-                $card['card_id'],
-                $card['card_type'],
-                $card['card_type_arg']
+                (int) $card['id'],
+                (int) $card['type'],
+                (int) $card['type_arg']
             ),
             $bgaCards
         );
@@ -656,11 +659,11 @@ private function getPlayersFromDatabase(): array {
 
         return array_map(
             fn (array $player) => new VelonimoPlayer(
-                $player['player_id'],
+                (int) $player['player_id'],
                 $player['player_name'],
-                $player['player_score'],
+                (int) $player['player_score'],
                 VelonimoPlayer::deserializeRoundsRanking($player['rounds_ranking']),
-                $player['is_wearing_jersey'],
+                ((int) $player['is_wearing_jersey']) === 1,
             ),
             $players
         );