diff --git a/src/ChestShop/EventListener.php b/src/ChestShop/EventListener.php
index 545ee09..1a2de1c 100644
--- a/src/ChestShop/EventListener.php
+++ b/src/ChestShop/EventListener.php
@@ -163,7 +163,7 @@ public function onSignChange(SignChangeEvent $event)
         if (!is_numeric($price) or $price < 0) return;
         if ($pID === false) return;
         if (($chest = $this->getSideChest($sign)) === false) return;
-        $shops = $this->databaseManager->selectByCondition(["shopOwner" => $shopOwner]);
+        $shops = $this->databaseManager->selectByCondition(["shopOwner" => "'$shopOwner'"]);
         if(!is_array($shops) or count($shops) + 1 > $this->plugin->getMaxPlayerShops($event->getPlayer())) return;
 
         $productName = ItemFactory::get($pID, $pMeta)->getName();