diff --git a/NEWS b/NEWS
index 1cad3a36..0ab8c449 100644
--- a/NEWS
+++ b/NEWS
@@ -10,6 +10,7 @@ NEWS ( CHANGELOG and HISTORY )                                     HTMLPurifier
 ==========================
 
 4.1.1, unknown release date
+- Fix undefined index warnings in maintenance scripts.
 - Fix bug in DirectLex for parsing elements with a single attribute
   with entities.
 - Rewrite CSS output logic for font-family and url().  Thanks Mario
diff --git a/maintenance/flush.php b/maintenance/flush.php
index 38ce5785..6dada93f 100644
--- a/maintenance/flush.php
+++ b/maintenance/flush.php
@@ -18,8 +18,7 @@ function e($cmd) {
     if ($status) exit($status);
 }
 
-$php = $_SERVER['argv'][1];
-if (!$php) $php = 'php';
+$php = empty($_SERVER['argv'][1]) ? 'php' : $_SERVER['argv'][1];
 
 e($php . ' generate-includes.php');
 e($php . ' generate-schema-cache.php');
diff --git a/maintenance/generate-includes.php b/maintenance/generate-includes.php
index 8a30c4ad..498f49b9 100644
--- a/maintenance/generate-includes.php
+++ b/maintenance/generate-includes.php
@@ -80,8 +80,9 @@ function get_dependency_lookup($file) {
         if (strncmp('class', $line, 5) === 0) {
             // The implementation here is fragile and will break if we attempt
             // to use interfaces. Beware!
-            list(, $parent) = explode(' extends ', trim($line, ' {'."\n\r"), 2);
-            if (empty($parent)) break;
+            $arr = explode(' extends ', trim($line, ' {'."\n\r"), 2);
+            if (count($arr) < 2) break;
+            $parent = $arr[1];
             $dep_file = HTMLPurifier_Bootstrap::getPath($parent);
             if (!$dep_file) break;
             $deps[$dep_file] = true;