diff --git a/src/unit/engine/NoseTestEngine.php b/src/unit/engine/NoseTestEngine.php
index e81bcb6..bea8c49 100644
--- a/src/unit/engine/NoseTestEngine.php
+++ b/src/unit/engine/NoseTestEngine.php
@@ -9,7 +9,16 @@ final class NoseTestEngine extends ArcanistUnitTestEngine {
 
   private $parser;
 
+  public function supportsRunAllTests() {
+    return true;
+  }
+
   public function run() {
+    if ($this->getRunAllTests()) {
+      $affected_tests = array(Filesystem::resolvePath("./"));
+      return $this->runTests($affected_tests, './');
+    }
+
     $paths = $this->getPaths();
 
     $affected_tests = array();