diff --git a/tests/FullTestSuite.php b/tests/FullTestSuite.php
index d5586e125..77e2dc6f9 100644
--- a/tests/FullTestSuite.php
+++ b/tests/FullTestSuite.php
@@ -1,35 +1,79 @@
 <?php
 @require_once('sapphire/tests/bootstrap.php');
 
+/**
+ * Alternative to letting PHPUnit handle class retrieval via
+ * traversing the filesystem. Works around restrictions of PHPUnit
+ * on running tests on multiple directories at once, without resorting
+ * to group or testsuite definitions in a custom phpunit.xml file.
+ * 
+ * Usage:
+ * - "phpunit sapphire/tests/FullTestSuite.php" 
+ *    (all tests)
+ * - "phpunit sapphire/tests/FullTestSuite.php '' module=sapphire,cms" 
+ *   (comma-separated modules. empty quotes are necessary to avoid PHPUnit argument confusion)
+ * 
+ * See http://www.phpunit.de/manual/current/en/organizing-tests.html#organizing-tests.testsuite
+ * 
+ * Note: We can't unit test this class because of segfaults in PHP5.3 when trying to
+ * use get_all_tests() within a SapphireTest.
+ * 
+ * @package sapphire
+ * @subpackage testing
+ */
 class FullTestSuite {
-
-	public static function get_tests() {
-		ManifestBuilder::load_test_manifest();
-		$tests = ClassInfo::subclassesFor('SapphireTest');
-		array_shift($tests);
-		unset($tests['FunctionalTest']);
-
-		// Remove tests that don't need to be executed every time
-		unset($tests['PhpSyntaxTest']);
-
-		foreach($tests as $class => $v) {
-			$reflection = new ReflectionClass($class);
-			if (!$reflection->isInstantiable()) {
-				unset($tests[$class]);
-			}
-		}
-		
-		return $tests;
-	}
-
+	
+	/**
+	 * Called by the PHPUnit runner to gather runnable tests.
+	 * 
+	 * @return PHPUnit_Framework_TestSuite
+	 */
 	public static function suite() {
 		$suite = new PHPUnit_Framework_TestSuite();
-		$classList = self::get_tests();
+		if(isset($_GET['module'])) {
+			$classList = self::get_module_tests($_GET['module']);
+		} else {
+			$classList = self::get_all_tests();
+		}
+
 		foreach($classList as $className) {
 			$suite->addTest(new SapphireTestSuite($className));
 		}
 
 		return $suite;
 	}
+
+	/**
+	 * @return Array
+	 */
+	public static function get_all_tests() {
+		ManifestBuilder::load_test_manifest();
+		$tests = ClassInfo::subclassesFor('SapphireTest');
+		array_shift($tests);
+		
+		return $tests;
+	}
+		
+	/**
+	 * Run tests for one or more "modules".
+	 * A module is generally a toplevel folder, e.g. "mysite" or "sapphire".
+	 * 
+	 * @param String $nameStr
+	 * @return Array
+	 */
+	protected static function get_module_tests($namesStr) {
+		$tests = array();
+		$names = explode(',', $namesStr);
+		foreach($names as $name) {
+			$classesForModule = ClassInfo::classes_for_folder($name);
+			if($classesForModule) foreach($classesForModule as $class) {
+				if(class_exists($class) && is_subclass_of($class, 'SapphireTest')) {
+					$tests[] = $class;
+				}
+			}
+		}
+
+		return $tests;
+	}
 }