diff --git a/lib/runner.js b/lib/runner.js
index 5512a2508..c757c399e 100644
--- a/lib/runner.js
+++ b/lib/runner.js
@@ -84,6 +84,12 @@ var addConfig = function(additionalConfig) {
 var cleanUp = function(runner) {
   var passed = runner.results().failedCount == 0;
   var exitCode = passed ? 0 : 1;
+  var exit = function(exitCode) {
+    if (typeof config.onCleanUp === 'function') {
+      config.onCleanUp(exitCode);
+    }
+    process.exit(exitCode);
+  };
   if (sauceAccount) {
     sauceAccount.updateJob(sessionId, {'passed': passed}, function(err) {
       if (err) {
@@ -91,15 +97,15 @@ var cleanUp = function(runner) {
           "Error updating Sauce pass/fail status: " + util.inspect(err)
         );
       }
-      process.exit(exitCode);
+      exit(exitCode);
     });
   } else if (server) {
     util.puts('Shutting down selenium standalone server.');
     server.stop().then(function() {
-      process.exit(exitCode);
+      exit(exitCode);
     });
   } else {
-    process.exit(exitCode);
+    exit(exitCode);
   }
 };
 
diff --git a/referenceConf.js b/referenceConf.js
index 046d9931e..2b5edbeb7 100644
--- a/referenceConf.js
+++ b/referenceConf.js
@@ -120,7 +120,7 @@ exports.config = {
     includeStackTrace: true,
     // Default time to wait in ms before a test fails.
     defaultTimeoutInterval: 30000
-  }
+  },
 
   // ----- Options to be passed to mocha -----
   //
@@ -128,5 +128,12 @@ exports.config = {
   mochaOpts: {
     ui: 'bdd',
     reporter: 'list'
-  }
+  },
+
+  // ----- The cleanup step -----
+  //
+  // A callback function called once the tests have finished running and
+  // the webdriver instance has been shut down. It is passed the exit code
+  // (0 if the tests passed or 1 if not).
+  onCleanUp: function() {}
 };