diff --git a/src/pocketmine/Player.php b/src/pocketmine/Player.php
index 35c5daf2b..c5b238b89 100644
--- a/src/pocketmine/Player.php
+++ b/src/pocketmine/Player.php
@@ -1630,7 +1630,7 @@ class Player extends Human implements CommandSender, InventoryHolder, ChunkLoade
 					$c = ord($packet->username{$i});
 					if(($c >= ord("a") and $c <= ord("z")) or
 						($c >= ord("A") and $c <= ord("Z")) or
-						($c >= ord("0") and $c <= ord("9")) or $c === "_"
+						($c >= ord("0") and $c <= ord("9")) or $c === ord("_")
 					){
 						continue;
 					}