diff --git a/testing/marionette/client/marionette/tests/unit/test_switch_remote_frame.py b/testing/marionette/client/marionette/tests/unit/test_switch_remote_frame.py
index 64d6a8bd1f73..0c2fb6cddffe 100644
--- a/testing/marionette/client/marionette/tests/unit/test_switch_remote_frame.py
+++ b/testing/marionette/client/marionette/tests/unit/test_switch_remote_frame.py
@@ -79,6 +79,36 @@ class TestSwitchRemoteFrame(MarionetteTestCase):
             """)
         self.assertFalse(main_process)
 
+    def test_we_can_switch_to_a_remote_frame_by_index(self):
+        # test if we can revisit a remote frame (this takes a different codepath)
+        self.marionette.navigate(self.marionette.absolute_url("test.html"))
+        self.marionette.execute_script("SpecialPowers.addPermission('browser', true, document)")
+        self.marionette.execute_script("""
+            let iframe = document.createElement("iframe");
+            SpecialPowers.wrap(iframe).mozbrowser = true;
+            SpecialPowers.wrap(iframe).remote = true;
+            iframe.id = "remote_iframe";
+            iframe.style.height = "100px";
+            iframe.style.width = "100%%";
+            iframe.src = "%s";
+            document.body.appendChild(iframe);
+            """ % self.marionette.absolute_url("test.html"))
+        self.marionette.switch_to_frame(0)
+        main_process = self.marionette.execute_script("""
+            return SpecialPowers.isMainProcess();
+            """)
+        self.assertFalse(main_process)
+        self.marionette.switch_to_frame()
+        main_process = self.marionette.execute_script("""
+            return SpecialPowers.isMainProcess();
+            """)
+        self.assertTrue(main_process)
+        self.marionette.switch_to_frame(0)
+        main_process = self.marionette.execute_script("""
+            return SpecialPowers.isMainProcess();
+            """)
+        self.assertFalse(main_process)
+
     def tearDown(self):
         if self.oop_by_default is None:
             self.marionette.execute_script("""
diff --git a/testing/marionette/client/marionette/tests/unit/unit-tests.ini b/testing/marionette/client/marionette/tests/unit/unit-tests.ini
index fcbcc9f46f2c..1bf4c06ba7ac 100644
--- a/testing/marionette/client/marionette/tests/unit/unit-tests.ini
+++ b/testing/marionette/client/marionette/tests/unit/unit-tests.ini
@@ -85,7 +85,6 @@ browser = false
 [test_switch_frame.py]
 [test_switch_frame_chrome.py]
 [test_switch_remote_frame.py]
-browser = false
 
 [test_pagesource.py]
 b2g = false
diff --git a/testing/marionette/marionette-listener.js b/testing/marionette/marionette-listener.js
index 9db68535e8c1..0527f6a8439f 100644
--- a/testing/marionette/marionette-listener.js
+++ b/testing/marionette/marionette-listener.js
@@ -1871,9 +1871,18 @@ function switchToFrame(msg) {
   }
   if (foundFrame == null) {
     if (typeof(msg.json.id) === 'number') {
-      foundFrame = frames[msg.json.id].frameElement;
-      curFrame = foundFrame;
-      foundFrame = elementManager.addToKnownElements(curFrame);
+      try {
+        foundFrame = frames[msg.json.id].frameElement;
+        curFrame = foundFrame;
+        foundFrame = elementManager.addToKnownElements(curFrame);
+      } catch (e) {
+        // Since window.frames does not return OOP frames it will throw
+        // and we land up here. Let's not give up and check if there are
+        // iframes and switch to the indexed frame there
+        let iframes = curFrame.document.getElementsByTagName("iframe");
+        curFrame = iframes[msg.json.id];
+        foundFrame = msg.json.id
+      }
     }
   }
   if (foundFrame == null) {