diff --git a/go_test_engine/__phutil_library_init__.php b/go_test_engine/__phutil_library_init__.php
new file mode 100644
index 0000000..08da3b4
--- /dev/null
+++ b/go_test_engine/__phutil_library_init__.php
@@ -0,0 +1,4 @@
+<?php
+
+phutil_register_library('go-test-engine', __FILE__);
+
diff --git a/go_test_engine/__phutil_library_map__.php b/go_test_engine/__phutil_library_map__.php
new file mode 100644
index 0000000..1c54447
--- /dev/null
+++ b/go_test_engine/__phutil_library_map__.php
@@ -0,0 +1,18 @@
+<?php
+
+/**
+ * This file is automatically generated. Use 'arc liberate' to rebuild it.
+ *
+ * @generated
+ * @phutil-library-version 2
+ */
+phutil_register_library_map(array(
+  '__library_version__' => 2,
+  'class' => array(
+    'GoTestEngine' => 'src/GoTestEngine.php',
+  ),
+  'function' => array(),
+  'xmap' => array(
+    'GoTestEngine' => 'ArcanistUnitTestEngine',
+  ),
+));
diff --git a/go_test_engine/src/GoTestEngine.php b/go_test_engine/src/GoTestEngine.php
new file mode 100644
index 0000000..c792def
--- /dev/null
+++ b/go_test_engine/src/GoTestEngine.php
@@ -0,0 +1,19 @@
+<?php
+final class GoTestEngine extends ArcanistUnitTestEngine {
+  public function run() {
+    $command = $this->getConfigurationManager()->getConfigFromAnySource('unit.engine.go.command');
+    $future = new ExecFuture($command);
+
+    do {
+      list($stdout, $stderr) = $future->read();
+      echo $stdout;
+      echo $stderr;
+      sleep(0.5);
+    } while (!$future->isReady());
+
+    list($error, $stdout, $stderr) = $future->resolve();
+
+    $parser = new ArcanistGoTestResultParser();
+    return $parser->parseTestResults("", $stdout);
+  }
+}
diff --git a/multi_test_engine/src/MultiTestEngine.php b/multi_test_engine/src/MultiTestEngine.php
index 44060b0..0cd9bcb 100644
--- a/multi_test_engine/src/MultiTestEngine.php
+++ b/multi_test_engine/src/MultiTestEngine.php
@@ -10,20 +10,65 @@ public function run() {
     $results = array();
 
     foreach ($engines as $engine_or_configuration) {
+      $include = false;
+      $includeReport = false;
+      $changedFileMatchesInclude = false;
+
       if (is_array($engine_or_configuration)) {
         $engine_class = $engine_or_configuration['engine'];
-
         foreach ($engine_or_configuration as $configuration => $value) {
-          if ($configuration != 'engine') {
+          if ($configuration != 'engine' &&
+              $configuration != 'include' &&
+              $configuration != 'include_report') {
             $config->setRuntimeConfig($configuration, $value);
           }
+
+          switch($configuration) {
+            case 'include':
+              $include = $value;
+              break;
+            case 'include_report':
+              $includeReport = $value
+              break
+          }
         }
       } else {
         $engine_class = $engine_or_configuration;
       }
 
       $engine = $this->instantiateEngine($engine_class);
-      $results = array_merge($results, $engine->run());
+
+      // If a regex is configured we'll do a match on all changed files to see if there's a match
+      // before calling $engine->run()
+      if ($include) {
+        $include = '/' . $include . '/';
+        foreach ($this->getPaths() as $path) {
+          if (preg_match($include, $path)) {
+            $changedFileMatchesInclude = true;
+            break;
+          }
+        }
+      }
+
+      // No need to execute the unit tests, so bail - but do report that we skipped running tests.
+      if (!$changedFileMatchesInclude) {
+        $test_results = [];
+        // Be silent by default if no files match the include regex, but if the config
+        // includes a bit to see it, output a skip test result for visibility when
+        // no tests match the include regex.
+        if ($includeReport) {
+          $skip_test = new ArcanistUnitTestResult();
+          $skip_test->setName("No changed files match " . $include . " - not running " . $engine_class);
+          $skip_test->setResult(ArcanistUnitTestResult::RESULT_SKIP);
+          $test_results[] = $skip_test;
+        }
+
+      // Actually run the tests if we didn't already decide not to run them.
+      } else {
+        $test_results = $engine->run();
+      }
+
+      $results = array_merge($results, $test_results);
     }
 
     return $results;