diff --git a/testing/web-platform/tests/tools/wptrunner/wptrunner/executors/executormarionette.py b/testing/web-platform/tests/tools/wptrunner/wptrunner/executors/executormarionette.py
index f7645fbea9df..959d9062b5cf 100644
--- a/testing/web-platform/tests/tools/wptrunner/wptrunner/executors/executormarionette.py
+++ b/testing/web-platform/tests/tools/wptrunner/wptrunner/executors/executormarionette.py
@@ -157,10 +157,9 @@ class MarionetteTestharnessProtocolPart(TestharnessProtocolPart):
 
         for handle in handles:
             try:
-                self.dismiss_alert(lambda: self.marionette.switch_to_window(handle))
-                self.marionette.switch_to_window(handle)
                 self.logger.info("Closing window %s" % handle)
-                self.marionette.close()
+                self.marionette.switch_to_window(handle)
+                self.dismiss_alert(lambda: self.marionette.close())
             except errors.NoSuchWindowException:
                 # We might have raced with the previous test to close this
                 # window, skip it.