diff --git a/core/ClassInfo.php b/core/ClassInfo.php
index 3c0a3daa2..b371f9682 100644
--- a/core/ClassInfo.php
+++ b/core/ClassInfo.php
@@ -59,34 +59,29 @@ class ClassInfo {
 	}
 
 	/**
-	 * Return the database tables linked to this class.
-	 * Gets an array of the current class, it subclasses and its ancestors.  It then filters that list
-	 * to those with DB tables
+	 * Returns an array of the current class and all its ancestors and children
+	 * which have a DB table.
 	 * 
-	 * @param mixed $class string of the classname or instance of the class
+	 * @param string|object $class
 	 * @todo Move this into data object
 	 * @return array
 	 */
-	static function dataClassesFor($class) {
-		global $_ALL_CLASSES;
-		if (is_object($class)) $class = get_class($class);
-		
-		$dataClasses = array();
-		
-		if(!$_ALL_CLASSES['parents'][$class]) user_error("ClassInfo::dataClassesFor() no parents for $class", E_USER_WARNING);
-		foreach($_ALL_CLASSES['parents'][$class] as $subclass) {
-			if(self::hasTable($subclass)) $dataClasses[] = $subclass;
-		}
-		
-		if(self::hasTable($class)) $dataClasses[] = $class;
+	public static function dataClassesFor($class) {
+		$result = array();
 
-		if(isset($_ALL_CLASSES['children'][$class]))
-		foreach($_ALL_CLASSES['children'][$class] as $subclass)
-		{
-			if(self::hasTable($subclass)) $dataClasses[] = $subclass;
+		if (is_object($class)) {
+			$class = get_class($class);
 		}
-			
-		return $dataClasses;
+
+		$classes = array_merge(
+			self::ancestry($class),
+			self::subclassesFor($class));
+
+		foreach ($classes as $class) {
+			if (self::hasTable($class)) $result[$class] = $class;
+		}
+
+		return $result;
 	}
 
 	/**
diff --git a/tests/ClassInfoTest.php b/tests/ClassInfoTest.php
index 194bc5757..f11d454fb 100644
--- a/tests/ClassInfoTest.php
+++ b/tests/ClassInfoTest.php
@@ -66,6 +66,26 @@ class ClassInfoTest extends SapphireTest {
 		ClassInfo::ancestry(42);
 	}
 
+	/**
+	 * @covers ClassInfo::dataClassesFor()
+	 */
+	public function testDataClassesFor() {
+		$expect = array(
+			'ClassInfoTest_BaseDataClass' => 'ClassInfoTest_BaseDataClass',
+			'ClassInfoTest_HasFields'     => 'ClassInfoTest_HasFields'
+		);
+
+		$classes = array(
+			'ClassInfoTest_BaseDataClass',
+			'ClassInfoTest_NoFields',
+			'ClassInfoTest_HasFields'
+		);
+
+		foreach ($classes as $class) {
+			$this->assertEquals($expect, ClassInfo::dataClassesFor($class));
+		}
+	}
+
 }
 
 class ClassInfoTest_BaseClass extends DataObject {
@@ -79,3 +99,11 @@ class ClassInfoTest_ChildClass extends ClassInfoTest_BaseClass {
 class ClassInfoTest_GrandChildClass extends ClassInfoTest_ChildClass {
 	
 }
+
+class ClassInfoTest_BaseDataClass extends DataObject {
+	public static $db = array('Title' => 'Varchar');
+}
+class ClassInfoTest_NoFields extends ClassInfoTest_BaseDataClass {}
+class ClassInfoTest_HasFields extends ClassInfoTest_NoFields {
+	public static $db = array('Description' => 'Varchar');
+}