diff --git a/adminer/sql.inc.php b/adminer/sql.inc.php
index 44ccef61..18f9badb 100644
--- a/adminer/sql.inc.php
+++ b/adminer/sql.inc.php
@@ -87,7 +87,7 @@ if (!$error && $_POST) {
 								$query .= fread($fp, 1e5);
 							} else {
 								$offset = $match[0][1] + strlen($s);
-								if ($s[0] != "\\") {
+								if (!isset($s[0]) || $s[0] != "\\") {
 									break;
 								}
 							}