diff --git a/inc/SP/Util/Checks.class.php b/inc/SP/Util/Checks.class.php
index 47283532..44fbe75d 100644
--- a/inc/SP/Util/Checks.class.php
+++ b/inc/SP/Util/Checks.class.php
@@ -292,7 +292,7 @@ class Checks
     {
         return
             (!empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off')
-            || $_SERVER['SERVER_PORT'] === 443;
+            || (int)$_SERVER['SERVER_PORT'] === 443;
     }
 
     /**
@@ -315,4 +315,4 @@ class Checks
     {
         return strpos(Request::getRequestHeaders('Accept'), 'application/json') === 0;
     }
-}
\ No newline at end of file
+}