diff --git a/src/unit/engine/ArcanistConfigurationDrivenUnitTestEngine.php b/src/unit/engine/ArcanistConfigurationDrivenUnitTestEngine.php
--- a/src/unit/engine/ArcanistConfigurationDrivenUnitTestEngine.php
+++ b/src/unit/engine/ArcanistConfigurationDrivenUnitTestEngine.php
@@ -74,6 +74,17 @@
         }
 
         $test_engine = clone $test_engines[$type];
+        $more = $test_engine->getEngineConfigurationOptions();
+
+        foreach ($more as $key => $option_spec) {
+          PhutilTypeSpec::checkMap(
+            $option_spec,
+            array(
+              'type' => 'string',
+              'help' => 'string',
+            ));
+          $more[$key] = $option_spec['type'];
+        }
       } else {
         // We'll raise an error below about the invalid "type" key.
         // TODO: Can we just do the type check first, and simplify this a bit?
@@ -87,7 +98,7 @@
             'type' => 'string',
             'include' => 'optional regex | list<regex>',
             'exclude' => 'optional regex | list<regex>',
-          ));
+          ) + $more);
       } catch (PhutilTypeCheckException $ex) {
         throw new PhutilProxyException(
           pht(
@@ -97,6 +108,22 @@
           $ex);
       }
 
+      foreach ($more as $key => $value) {
+        if (array_key_exists($key, $spec)) {
+          try {
+            $test_engine->setEngineConfigurationValue($key, $spec[$key]);
+          } catch (Exception $ex) {
+            throw new PhutilProxyException(
+              pht(
+                "Error in parsing '%s' file, in key '%s' for test engine '%s'.",
+                '.arcunit',
+                $key,
+                $name),
+              $ex);
+          }
+        }
+      }
+
       if ($all_paths) {
         $include = (array)idx($spec, 'include', array());
         $exclude = (array)idx($spec, 'exclude', array());
diff --git a/src/unit/engine/ArcanistUnitTestEngine.php b/src/unit/engine/ArcanistUnitTestEngine.php
--- a/src/unit/engine/ArcanistUnitTestEngine.php
+++ b/src/unit/engine/ArcanistUnitTestEngine.php
@@ -18,6 +18,14 @@
     return null;
   }
 
+  public function getEngineConfigurationOptions() {
+    return array();
+  }
+
+  public function setEngineConfigurationValue($key, $value) {
+    throw new Exception(pht('Incomplete implementation: %s!', $key));
+  }
+
   final public function setRunAllTests($run_all_tests) {
     if (!$this->supportsRunAllTests() && $run_all_tests) {
       throw new Exception(