diff --git a/src/unit/engine/NoseTestEngine.php b/src/unit/engine/NoseTestEngine.php
index 039daf5e..1391d135 100644
--- a/src/unit/engine/NoseTestEngine.php
+++ b/src/unit/engine/NoseTestEngine.php
@@ -9,7 +9,17 @@ final class NoseTestEngine extends ArcanistUnitTestEngine {
 
   private $parser;
 
+  protected function supportsRunAllTests() {
+    return true;
+  }
+
   public function run() {
+    if ($this->getRunAllTests()) {
+      $root = $this->getWorkingCopy()->getProjectRoot();
+      $all_tests = glob(Filesystem::resolvePath("$root/tests/**/test_*.py"));
+      return $this->runTests($all_tests, $root);
+    }
+
     $paths = $this->getPaths();
 
     $affected_tests = array();