--- a/testing/marionette/client/marionette/runner/base.py
+++ b/testing/marionette/client/marionette/runner/base.py
@@ -937,16 +937,19 @@ setReq.onerror = function() {
             self.tests = chunks[self.this_chunk - 1]
 
         self.run_test_set(self.tests)
 
     def cleanup(self):
         if self.httpd:
             self.httpd.stop()
 
+        if self.marionette:
+            self.marionette.cleanup()
+
     __del__ = cleanup
 
     def generate_xml(self, results_list):
 
         def _extract_xml_from_result(test_result, result='passed'):
             _extract_xml(
                 test_name=unicode(test_result.name).split()[0],
                 test_class=test_result.test_class,