diff --git a/library/HTMLPurifier.includes.php b/library/HTMLPurifier.includes.php
index 8039d459..5daef582 100644
--- a/library/HTMLPurifier.includes.php
+++ b/library/HTMLPurifier.includes.php
@@ -135,6 +135,7 @@ require 'HTMLPurifier/ConfigSchema/Validator/Alnum.php';
 require 'HTMLPurifier/ConfigSchema/Validator/Exists.php';
 require 'HTMLPurifier/ConfigSchema/Validator/NamespaceExists.php';
 require 'HTMLPurifier/ConfigSchema/Validator/ParseId.php';
+require 'HTMLPurifier/ConfigSchema/Validator/ParseType.php';
 require 'HTMLPurifier/ConfigSchema/Validator/Unique.php';
 require 'HTMLPurifier/DefinitionCache/Decorator.php';
 require 'HTMLPurifier/DefinitionCache/Null.php';
diff --git a/library/HTMLPurifier/ConfigSchema/Interchange.php b/library/HTMLPurifier/ConfigSchema/Interchange.php
index e2fc6c05..57b0c9cd 100644
--- a/library/HTMLPurifier/ConfigSchema/Interchange.php
+++ b/library/HTMLPurifier/ConfigSchema/Interchange.php
@@ -57,17 +57,28 @@ class HTMLPurifier_ConfigSchema_Interchange
         $validator = new HTMLPurifier_ConfigSchema_InterchangeValidator($this);
         
         // Validators should be defined in the order they are to be called.
+        
+        // ID tests
         $validator->addValidator($this->make('Exists', 'ID'));
         $validator->addValidator($this->make('Unique'));
         $validator->addNamespaceValidator($this->make('Alnum', 'ID'));
         $validator->addValidator($this->make('ParseId'));
         $validator->addValidator($this->make('Exists', '_NAMESPACE'));
         $validator->addValidator($this->make('Alnum', '_NAMESPACE'));
+        
+        // Directive tests
         $validator->addDirectiveValidator($this->make('Exists', '_DIRECTIVE'));
         $validator->addDirectiveValidator($this->make('Alnum', '_DIRECTIVE'));
-        $validator->addDirectiveValidator($this->make('Exists', 'TYPE'));
-        $validator->addDirectiveValidator($this->make('Exists', 'DEFAULT'));
         $validator->addDirectiveValidator($this->make('NamespaceExists'));
+        
+        // Directive: Type tests
+        $validator->addDirectiveValidator($this->make('Exists', 'TYPE'));
+        $validator->addDirectiveValidator($this->make('ParseType'));
+        $validator->addDirectiveValidator($this->make('Exists', '_TYPE'));
+        $validator->addDirectiveValidator($this->make('Exists', '_NULL'));
+        $validator->addDirectiveValidator($this->make('Exists', 'DEFAULT'));
+        
+        // Common tests
         $validator->addValidator($this->make('Exists', 'DESCRIPTION'));
         
         return $validator;
diff --git a/library/HTMLPurifier/ConfigSchema/Validator/ParseType.php b/library/HTMLPurifier/ConfigSchema/Validator/ParseType.php
new file mode 100644
index 00000000..dc0a4dab
--- /dev/null
+++ b/library/HTMLPurifier/ConfigSchema/Validator/ParseType.php
@@ -0,0 +1,19 @@
+<?php
+
+/**
+ * Parses TYPE into _TYPE and _NULL. Expects TYPE and ID to exist.
+ */
+class HTMLPurifier_ConfigSchema_Validator_ParseType extends HTMLPurifier_ConfigSchema_Validator
+{
+    
+    public function validate(&$arr, $interchange) {
+        $r = explode('/', $arr['TYPE'], 2);
+        if (!isset($interchange->types[$r[0]])) {
+            $this->error('Invalid type ' . $r[0] . ' for configuration directive ' . $arr['ID']);
+        }
+        $arr['_TYPE'] = $r[0];
+        $arr['_NULL'] = (isset($r[1]) && $r[1] === 'null');
+        
+    }
+    
+}
diff --git a/tests/HTMLPurifier/ConfigSchema/Validator/ParseTypeTest.php b/tests/HTMLPurifier/ConfigSchema/Validator/ParseTypeTest.php
new file mode 100644
index 00000000..f84f7b71
--- /dev/null
+++ b/tests/HTMLPurifier/ConfigSchema/Validator/ParseTypeTest.php
@@ -0,0 +1,34 @@
+<?php
+
+class HTMLPurifier_ConfigSchema_Validator_ParseTypeTest extends HTMLPurifier_ConfigSchema_ValidatorHarness
+{
+    
+    public function testValidatePlain() {
+        $arr = array('ID' => 'N.D', 'TYPE' => 'string');
+        $this->validator->validate($arr, $this->interchange);
+        $this->assertIdentical($arr, array(
+            'ID' => 'N.D',
+            'TYPE' => 'string',
+            '_TYPE' => 'string',
+            '_NULL' => false,
+        ));
+    }
+    
+    public function testValidateWithNull() {
+        $arr = array('ID' => 'N.D', 'TYPE' => 'int/null');
+        $this->validator->validate($arr, $this->interchange);
+        $this->assertIdentical($arr, array(
+            'ID' => 'N.D',
+            'TYPE' => 'int/null',
+            '_TYPE' => 'int',
+            '_NULL' => true,
+        ));
+    }
+    
+    public function testValidateInvalidType() {
+        $arr = array('ID' => 'N.D', 'TYPE' => 'aint/null');
+        $this->expectSchemaException('Invalid type aint for configuration directive N.D');
+        $this->validator->validate($arr, $this->interchange);
+    }
+    
+}