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
@@ -7,7 +7,6 @@
 
   private $workingCopy;
   private $paths = array();
-  private $arguments = array();
   private $enableCoverage;
   private $runAllTests;
   private $configurationManager;
@@ -70,15 +69,6 @@
     return $this->paths;
   }
 
-  final public function setArguments(array $arguments) {
-    $this->arguments = $arguments;
-    return $this;
-  }
-
-  final public function getArgument($key, $default = null) {
-    return idx($this->arguments, $key, $default);
-  }
-
   final public function setEnableCoverage($enable_coverage) {
     $this->enableCoverage = $enable_coverage;
     return $this;
diff --git a/src/workflow/ArcanistUnitWorkflow.php b/src/workflow/ArcanistUnitWorkflow.php
--- a/src/workflow/ArcanistUnitWorkflow.php
+++ b/src/workflow/ArcanistUnitWorkflow.php
@@ -151,7 +151,6 @@
     } else {
       $this->engine->setPaths($paths);
     }
-    $this->engine->setArguments($this->getPassthruArgumentsAsMap('unit'));
 
     $renderer = new ArcanistUnitConsoleRenderer();
     $this->engine->setRenderer($renderer);