diff --git a/library/HTMLPurifier.includes.php b/library/HTMLPurifier.includes.php
index aeecdb97..6e86c36e 100644
--- a/library/HTMLPurifier.includes.php
+++ b/library/HTMLPurifier.includes.php
@@ -133,6 +133,7 @@ require 'HTMLPurifier/ConfigSchema/StringHashReverseAdapter.php';
 require 'HTMLPurifier/ConfigSchema/Validator.php';
 require 'HTMLPurifier/ConfigSchema/Validator/Alnum.php';
 require 'HTMLPurifier/ConfigSchema/Validator/Exists.php';
+require 'HTMLPurifier/ConfigSchema/Validator/Unique.php';
 require 'HTMLPurifier/DefinitionCache/Decorator.php';
 require 'HTMLPurifier/DefinitionCache/Null.php';
 require 'HTMLPurifier/DefinitionCache/Serializer.php';
diff --git a/library/HTMLPurifier/ConfigSchema.php b/library/HTMLPurifier/ConfigSchema.php
index 7909db22..48177624 100644
--- a/library/HTMLPurifier/ConfigSchema.php
+++ b/library/HTMLPurifier/ConfigSchema.php
@@ -158,22 +158,6 @@ class HTMLPurifier_ConfigSchema {
      * @param $description Description of the namespace
      */
     public function addNamespace($namespace, $description) {
-        if (HTMLPURIFIER_SCHEMA_STRICT) {
-            if (isset($this->info[$namespace])) {
-                trigger_error('Cannot redefine namespace', E_USER_ERROR);
-                return;
-            }
-            if (!ctype_alnum($namespace)) {
-                trigger_error('Namespace name must be alphanumeric',
-                    E_USER_ERROR);
-                return;
-            }
-            if (empty($description)) {
-                trigger_error('Description must be non-empty',
-                    E_USER_ERROR);
-                return;
-            }
-        }
         $this->info[$namespace] = array();
         $this->info_namespace[$namespace] = new HTMLPurifier_ConfigDef_Namespace();
         $this->info_namespace[$namespace]->description = $description;
diff --git a/library/HTMLPurifier/ConfigSchema/Interchange.php b/library/HTMLPurifier/ConfigSchema/Interchange.php
index d9d98e2f..d44cf4c3 100644
--- a/library/HTMLPurifier/ConfigSchema/Interchange.php
+++ b/library/HTMLPurifier/ConfigSchema/Interchange.php
@@ -60,7 +60,7 @@ class HTMLPurifier_ConfigSchema_Interchange
         
         // Common validators
         $validator->addValidator(new HTMLPurifier_ConfigSchema_Validator_Exists('ID'));
-        $validator->addValidator(new HTMLPurifier_ConfigSchema_Validator_Duplicate());
+        $validator->addValidator(new HTMLPurifier_ConfigSchema_Validator_Unique());
         $validator->addValidator(new HTMLPurifier_ConfigSchema_Validator_Exists('DESCRIPTION'));
         
         // Namespace validators
diff --git a/library/HTMLPurifier/ConfigSchema/Validator/Duplicate.php b/library/HTMLPurifier/ConfigSchema/Validator/Unique.php
similarity index 85%
rename from library/HTMLPurifier/ConfigSchema/Validator/Duplicate.php
rename to library/HTMLPurifier/ConfigSchema/Validator/Unique.php
index bcada41d..6775f025 100644
--- a/library/HTMLPurifier/ConfigSchema/Validator/Duplicate.php
+++ b/library/HTMLPurifier/ConfigSchema/Validator/Unique.php
@@ -6,7 +6,7 @@
  *      Although this tests both possible values, in practice the ID
  *      will only be in one or the other. We do this to keep things simple.
  */
-class HTMLPurifier_ConfigSchema_Validator_Duplicate extends HTMLPurifier_ConfigSchema_Validator
+class HTMLPurifier_ConfigSchema_Validator_Unique extends HTMLPurifier_ConfigSchema_Validator
 {
     
     public function validate(&$arr, $interchange) {
diff --git a/tests/HTMLPurifier/ConfigSchema/Validator/DuplicateTest.php b/tests/HTMLPurifier/ConfigSchema/Validator/UniqueTest.php
similarity index 86%
rename from tests/HTMLPurifier/ConfigSchema/Validator/DuplicateTest.php
rename to tests/HTMLPurifier/ConfigSchema/Validator/UniqueTest.php
index ac3fd4e3..fce84e11 100644
--- a/tests/HTMLPurifier/ConfigSchema/Validator/DuplicateTest.php
+++ b/tests/HTMLPurifier/ConfigSchema/Validator/UniqueTest.php
@@ -1,11 +1,11 @@
 <?php
 
-class HTMLPurifier_ConfigSchema_Validator_DuplicateTest extends HTMLPurifier_ConfigSchema_ValidatorHarness
+class HTMLPurifier_ConfigSchema_Validator_UniqueTest extends HTMLPurifier_ConfigSchema_ValidatorHarness
 {
     
     public function setup() {
         parent::setup();
-        $this->validator = new HTMLPurifier_ConfigSchema_Validator_Duplicate();
+        $this->validator = new HTMLPurifier_ConfigSchema_Validator_Unique();
     }
     
     public function testValidateNamespace() {
diff --git a/tests/HTMLPurifier/ConfigSchemaTest.php b/tests/HTMLPurifier/ConfigSchemaTest.php
index 49abf145..b4e388da 100644
--- a/tests/HTMLPurifier/ConfigSchemaTest.php
+++ b/tests/HTMLPurifier/ConfigSchemaTest.php
@@ -19,15 +19,6 @@ class HTMLPurifier_ConfigSchemaTest extends HTMLPurifier_Harness
         $this->assertIdentical($this->schema->info_namespace, array(
             'http' => new HTMLPurifier_ConfigDef_Namespace($d)
         ));
-        
-        $this->expectError('Cannot redefine namespace');
-        $this->schema->addNamespace('http', 'It is used to serve webpages.');
-        
-        $this->expectError('Namespace name must be alphanumeric');
-        $this->schema->addNamespace('ssh+http', 'This http is tunneled through SSH.');
-        
-        $this->expectError('Description must be non-empty');
-        $this->schema->addNamespace('ftp', null);
     }
     
     function test_define() {
diff --git a/tests/index.php b/tests/index.php
index 45eab7c9..b045b804 100755
--- a/tests/index.php
+++ b/tests/index.php
@@ -57,6 +57,16 @@ if ($AC['disable-phpt'] && $AC['only-phpt']) {
     exit(1);
 }
 
+// Shell-script code is executed
+
+if ($AC['flush']) {
+    if (SimpleReporter::inCli() && !$AC['xml']) {
+        passthru($AC['php'] . ' ../maintenance/flush.php');
+    } else {
+        shell_exec($AC['php'] . ' ../maintenance/flush.php');
+    }
+}
+
 // initialize and load HTML Purifier
 // use ?standalone to load the alterative standalone stub
 if ($AC['standalone']) {
@@ -68,16 +78,6 @@ if ($AC['standalone']) {
 }
 require 'HTMLPurifier/Harness.php';
 
-// Shell-script code is executed
-
-if ($AC['flush']) {
-    if (SimpleReporter::inCli() && !$AC['xml']) {
-        passthru($AC['php'] . ' ../maintenance/flush.php');
-    } else {
-        shell_exec($AC['php'] . ' ../maintenance/flush.php');
-    }
-}
-
 // Now, userland code begins to be executed
 
 // setup special DefinitionCacheFactory decorator