diff --git a/index.php.template.txt b/index.php.template.txt
index 5bb42ccbd..6654d75a2 100644
--- a/index.php.template.txt
+++ b/index.php.template.txt
@@ -59,7 +59,7 @@ if ($psim) {
 		if (substr($server, $hyphenpos + 1) === 'afd') {
 			$afd = true;
 			$server = substr($server, 0, $hyphenpos);
-		} else {
+		} else if (ctype_digit(substr($server, $hyphenpos + 1))) {
 			$serverport = substr($server, $hyphenpos + 1);
 			$server = substr($server, 0, $hyphenpos);
 		}