diff --git a/src/pocketmine/plugin/PluginDescription.php b/src/pocketmine/plugin/PluginDescription.php
index a53b5b27d..dc7be00e8 100644
--- a/src/pocketmine/plugin/PluginDescription.php
+++ b/src/pocketmine/plugin/PluginDescription.php
@@ -69,9 +69,9 @@ class PluginDescription{
 			throw new PluginException("Invalid PluginDescription name");
 		}
 		$this->name = str_replace(" ", "_", $this->name);
-		$this->version = $plugin["version"];
+		$this->version = (string) $plugin["version"];
 		$this->main = $plugin["main"];
-		$this->api = !is_array($plugin["api"]) ? [$plugin["api"]] : $plugin["api"];
+		$this->api = array_map(function($v){ return (string) $v; }, !is_array($plugin["api"]) ? [$plugin["api"]] : $plugin["api"]);
 		if(stripos($this->main, "pocketmine\\") === 0){
 			throw new PluginException("Invalid PluginDescription main, cannot start within the PocketMine namespace");
 		}