diff --git a/core/valuesetdef/ValueSetEnumClasses.php b/core/valuesetdef/ValueSetEnumClasses.php
new file mode 100644
index 0000000000..b2788f738f
--- /dev/null
+++ b/core/valuesetdef/ValueSetEnumClasses.php
@@ -0,0 +1,43 @@
+<?php
+
+/**
+ * Data model classes
+ *
+ * @package     iTopORM
+ */
+class ValueSetEnumClasses extends ValueSetEnum
+{
+    protected $m_sCategories;
+
+    public function __construct($sCategories = '', $sAdditionalValues = '')
+    {
+        $this->m_sCategories = $sCategories;
+        parent::__construct($sAdditionalValues, true /* Classes are always sorted alphabetically */);
+    }
+
+    protected function LoadValues($aArgs)
+    {
+        // Call the parent to parse the additional values...
+        parent::LoadValues($aArgs);
+
+        // Translate the labels of the additional values
+        foreach ($this->m_aValues as $sClass => $void) {
+            if (MetaModel::IsValidClass($sClass)) {
+                $this->m_aValues[$sClass] = MetaModel::GetName($sClass);
+            } else {
+                unset($this->m_aValues[$sClass]);
+            }
+        }
+
+        // Then, add the classes from the category definition
+        foreach (MetaModel::GetClasses($this->m_sCategories) as $sClass) {
+            if (MetaModel::IsValidClass($sClass)) {
+                $this->m_aValues[$sClass] = MetaModel::GetName($sClass);
+            } else {
+                unset($this->m_aValues[$sClass]);
+            }
+        }
+
+        return true;
+    }
+}
\ No newline at end of file