diff --git a/SourceQuery/SourceQuery.php b/SourceQuery/SourceQuery.php
index 53f6b10..8ab1a95 100644
--- a/SourceQuery/SourceQuery.php
+++ b/SourceQuery/SourceQuery.php
@@ -95,7 +95,7 @@ class SourceQuery
 		 */
 		private bool $UseOldGetChallengeMethod = false;
 		
-		public function __construct( BaseSocket $Socket = null )
+		public function __construct( ?BaseSocket $Socket = null )
 		{
 			$this->Socket = $Socket ?: new Socket( );
 		}