diff --git a/testing/marionette/client/marionette/marionette_test.py b/testing/marionette/client/marionette/marionette_test.py
index 97454b25a4f0..6f0ecb96242e 100644
--- a/testing/marionette/client/marionette/marionette_test.py
+++ b/testing/marionette/client/marionette/marionette_test.py
@@ -21,7 +21,7 @@ from marionette_driver.errors import (
         StaleElementException, ScriptTimeoutException, ElementNotVisibleException,
         NoSuchFrameException, InvalidElementStateException, NoAlertPresentException,
         InvalidCookieDomainException, UnableToSetCookieException, InvalidSelectorException,
-        MoveTargetOutOfBoundsException, FrameSendNotInitializedError, FrameSendFailureError
+        MoveTargetOutOfBoundsException
         )
 from marionette_driver.marionette import Marionette
 from marionette_driver.wait import Wait
diff --git a/testing/marionette/driver/marionette_driver/errors.py b/testing/marionette/driver/marionette_driver/errors.py
index a745caecc8b8..31affbfa7c9c 100644
--- a/testing/marionette/driver/marionette_driver/errors.py
+++ b/testing/marionette/driver/marionette_driver/errors.py
@@ -150,16 +150,6 @@ class MoveTargetOutOfBoundsException(MarionetteException):
     status = "move target out of bounds"
 
 
-class FrameSendNotInitializedError(MarionetteException):
-    code = (54,)
-    status = "frame send not initialized"
-
-
-class FrameSendFailureError(MarionetteException):
-    code = (55,)
-    status = "frame send failure"
-
-
 class SessionNotCreatedException(MarionetteException):
     code = (33, 71)
     status = "session not created"