diff --git a/library/HTMLPurifier/AttrDef/Length.php b/library/HTMLPurifier/AttrDef/Length.php
index 6fb443a9..f2a44c20 100644
--- a/library/HTMLPurifier/AttrDef/Length.php
+++ b/library/HTMLPurifier/AttrDef/Length.php
@@ -11,7 +11,7 @@ class HTMLPurifier_AttrDef_Length extends HTMLPurifier_AttrDef_Pixels
         $string = trim($string);
         if ($string === '') return false;
         
-        $parent_result = parent::validate($string);
+        $parent_result = parent::validate($string, $config, $context);
         if ($parent_result !== false) return $parent_result;
         
         $length = strlen($string);
diff --git a/library/HTMLPurifier/AttrDef/MultiLength.php b/library/HTMLPurifier/AttrDef/MultiLength.php
index c89ca198..d14ecfee 100644
--- a/library/HTMLPurifier/AttrDef/MultiLength.php
+++ b/library/HTMLPurifier/AttrDef/MultiLength.php
@@ -11,7 +11,7 @@ class HTMLPurifier_AttrDef_MultiLength extends HTMLPurifier_AttrDef_Length
         $string = trim($string);
         if ($string === '') return false;
         
-        $parent_result = parent::validate($string);
+        $parent_result = parent::validate($string, $config, $context);
         if ($parent_result !== false) return $parent_result;
         
         $length = strlen($string);
diff --git a/tests/HTMLPurifier/AttrDef/URITest.php b/tests/HTMLPurifier/AttrDef/URITest.php
index 9a1ffad9..0c079b33 100644
--- a/tests/HTMLPurifier/AttrDef/URITest.php
+++ b/tests/HTMLPurifier/AttrDef/URITest.php
@@ -175,6 +175,12 @@ class HTMLPurifier_AttrDef_URITest extends HTMLPurifier_AttrDefHarness
             if (!isset($expect_uri[$i])) {
                 $expect_uri[$i] = $value;
             }
+            if (!isset($config[$i])) {
+                $config[$i] = HTMLPurifier_Config::createDefault();
+            }
+            if (!isset($context[$i])) {
+                $context[$i] = new HTMLPurifier_AttrContext();
+            }
             if ($components[$i] === false) {
                 $scheme->expectNever('validateComponents');
             } else {
@@ -182,7 +188,7 @@ class HTMLPurifier_AttrDef_URITest extends HTMLPurifier_AttrDefHarness
                     'validateComponents', $return_components[$i], $components[$i]);
                 $scheme->expectOnce('validateComponents', $components[$i]);
             }
-            $result = $def->validate($value);
+            $result = $def->validate($value, $config[$i], $context[$i]);
             $scheme->tally();
             $this->assertIdentical($expect_uri[$i], $result, "Test $i: %s");