diff --git a/NEWS b/NEWS
index 7a2d4236..c028c486 100644
--- a/NEWS
+++ b/NEWS
@@ -17,6 +17,7 @@ NEWS ( CHANGELOG and HISTORY )                                     HTMLPurifier
 - Escape CDATA before removing Internet Explorer comments.
 - Fix removal of id attributes under certain conditions by ensuring
   armor attributes are preserved when recreating tags.
+- Check if schema.ser was corrupted.
 
 4.2.0, released 2010-09-15
 ! Added %Core.RemoveProcessingInstructions, which lets you remove
diff --git a/library/HTMLPurifier/ConfigSchema.php b/library/HTMLPurifier/ConfigSchema.php
index 67be5c71..fadf7a58 100644
--- a/library/HTMLPurifier/ConfigSchema.php
+++ b/library/HTMLPurifier/ConfigSchema.php
@@ -60,7 +60,13 @@ class HTMLPurifier_ConfigSchema {
      * Unserializes the default ConfigSchema.
      */
     public static function makeFromSerial() {
-        return unserialize(file_get_contents(HTMLPURIFIER_PREFIX . '/HTMLPurifier/ConfigSchema/schema.ser'));
+        $contents = file_get_contents(HTMLPURIFIER_PREFIX . '/HTMLPurifier/ConfigSchema/schema.ser');
+        $r = unserialize($contents);
+        if (!$r) {
+            $hash = sha1($contents);
+            trigger_error("Unserialization of configuration schema failed, sha1 of file was $hash", E_USER_ERROR);
+        }
+        return $r;
     }
 
     /**