diff --git a/testing/marionette/client/marionette/b2g_update_test.py b/testing/marionette/client/marionette/b2g_update_test.py
index 5c832922e469..3f7c8cfe1327 100644
--- a/testing/marionette/client/marionette/b2g_update_test.py
+++ b/testing/marionette/client/marionette/b2g_update_test.py
@@ -11,11 +11,11 @@ import time
 import types
 import weakref
 
-from b2ginstance import B2GInstance
-from marionette_driver.errors import InvalidResponseException
 from marionette_driver.marionette import Marionette
 from marionette_test import MarionetteTestCase
 from marionette_transport import MarionetteTransport
+
+from b2ginstance import B2GInstance
 from runtests import MarionetteTestRunner, cli
 
 class B2GUpdateMarionetteClient(MarionetteTransport):
@@ -237,16 +237,10 @@ class B2GUpdateTestCase(MarionetteTestCase):
 
         self.print_status(status, os.path.basename(path))
 
-        try:
-            results = self.marionette.execute_async_script(data,
-                                                           script_args=[self.testvars],
-                                                           special_powers=True)
-            self.handle_results(path, stage, results)
-        except InvalidResponseException, e:
-            # If the update test causes a restart, we will get an invalid
-            # response from the socket here.
-            if not will_restart:
-                raise e
+        results = self.marionette.execute_async_script(data,
+                                                       script_args=[self.testvars],
+                                                       special_powers=True)
+        self.handle_results(path, stage, results)
 
     def handle_results(self, path, stage, results):
         passed = results['passed']
diff --git a/testing/marionette/client/marionette/marionette_test.py b/testing/marionette/client/marionette/marionette_test.py
index a1c56370d4df..bf6ed1f5f2ad 100644
--- a/testing/marionette/client/marionette/marionette_test.py
+++ b/testing/marionette/client/marionette/marionette_test.py
@@ -16,8 +16,8 @@ import warnings
 
 
 from marionette_driver.errors import (
-        MarionetteException, InstallGeckoError, TimeoutException, InvalidResponseException,
-        JavascriptException, NoSuchElementException, XPathLookupException, NoSuchWindowException,
+        MarionetteException, TimeoutException,
+        JavascriptException, NoSuchElementException, NoSuchWindowException,
         StaleElementException, ScriptTimeoutException, ElementNotVisibleException,
         NoSuchFrameException, InvalidElementStateException, NoAlertPresentException,
         InvalidCookieDomainException, UnableToSetCookieException, InvalidSelectorException,
diff --git a/testing/marionette/driver/marionette_driver/errors.py b/testing/marionette/driver/marionette_driver/errors.py
index 34473cf7d443..d8256dca927b 100644
--- a/testing/marionette/driver/marionette_driver/errors.py
+++ b/testing/marionette/driver/marionette_driver/errors.py
@@ -49,8 +49,16 @@ class MarionetteException(Exception):
         return "".join(traceback.format_exception(self.__class__, msg, tb))
 
 
-class InstallGeckoError(MarionetteException):
-    pass
+class ElementNotSelectableException(MarionetteException):
+    status = "element not selectable"
+
+
+class InvalidArgumentException(MarionetteException):
+    status = "invalid argument"
+
+
+class InvalidSessionIdException(MarionetteException):
+    status = "invalid session id"
 
 
 class TimeoutException(MarionetteException):
@@ -58,11 +66,6 @@ class TimeoutException(MarionetteException):
     status = "timeout"
 
 
-class InvalidResponseException(MarionetteException):
-    code = (53,)
-    status = "invalid response"
-
-
 class JavascriptException(MarionetteException):
     code = (17,)
     status = "javascript error"
@@ -73,11 +76,6 @@ class NoSuchElementException(MarionetteException):
     status = "no such element"
 
 
-class XPathLookupException(MarionetteException):
-    code = (19,)
-    status = "invalid xpath selector"
-
-
 class NoSuchWindowException(MarionetteException):
     code = (23,)
     status = "no such window"
@@ -159,11 +157,6 @@ class FrameSendFailureError(MarionetteException):
     status = "frame send failure"
 
 
-class UnsupportedOperationException(MarionetteException):
-    code = (405,)
-    status = "unsupported operation"
-
-
 class SessionNotCreatedException(MarionetteException):
     code = (33, 71)
     status = "session not created"
@@ -173,31 +166,50 @@ class UnexpectedAlertOpen(MarionetteException):
     code = (26,)
     status = "unexpected alert open"
 
+
+class UnknownCommandException(MarionetteException):
+    code = (9,)
+    status = "unknown command"
+
+
+class UnknownException(MarionetteException):
+    code = (13,)
+    status = "unknown error"
+
+
+class UnsupportedOperationException(MarionetteException):
+    code = (405,)
+    status = "unsupported operation"
+
+
 excs = [
-  MarionetteException,
-  TimeoutException,
-  InvalidResponseException,
-  JavascriptException,
-  NoSuchElementException,
-  XPathLookupException,
-  NoSuchWindowException,
-  StaleElementException,
-  ScriptTimeoutException,
-  ElementNotVisibleException,
   ElementNotAccessibleException,
-  NoSuchFrameException,
-  InvalidElementStateException,
-  NoAlertPresentException,
-  InvalidCookieDomainException,
-  UnableToSetCookieException,
-  InvalidElementCoordinates,
-  InvalidSelectorException,
-  MoveTargetOutOfBoundsException,
-  FrameSendNotInitializedError,
+  ElementNotSelectableException,
+  ElementNotVisibleException,
   FrameSendFailureError,
-  UnsupportedOperationException,
+  FrameSendNotInitializedError,
+  InvalidArgumentException,
+  InvalidCookieDomainException,
+  InvalidElementCoordinates,
+  InvalidElementStateException,
+  InvalidSelectorException,
+  InvalidSessionIdException,
+  JavascriptException,
+  MarionetteException,
+  MoveTargetOutOfBoundsException,
+  NoAlertPresentException,
+  NoSuchElementException,
+  NoSuchFrameException,
+  NoSuchWindowException,
+  ScriptTimeoutException,
   SessionNotCreatedException,
+  StaleElementException,
+  TimeoutException,
+  UnableToSetCookieException,
   UnexpectedAlertOpen,
+  UnknownCommandException,
+  UnknownException,
+  UnsupportedOperationException,
 ]
 
 
diff --git a/testing/marionette/error.js b/testing/marionette/error.js
index 4921af21d44d..0a916b420a1e 100644
--- a/testing/marionette/error.js
+++ b/testing/marionette/error.js
@@ -14,6 +14,7 @@ const errors = [
   "IllegalArgumentError",
   "InvalidElementStateError",
   "InvalidSelectorError",
+  "InvalidSessionIdError",
   "JavaScriptError",
   "NoAlertOpenError",
   "NoSuchElementError",
@@ -211,6 +212,14 @@ this.InvalidSelectorError = function(msg) {
 };
 InvalidSelectorError.prototype = Object.create(WebDriverError.prototype);
 
+this.InvalidSessionIdError = function(msg) {
+  WebDriverError.call(this, msg);
+  this.name = "InvalidSessionIdError";
+  this.status = "invalid session id";
+  this.code = 13;
+};
+InvalidSessionIdError.prototype = Object.create(WebDriverError.prototype);
+
 /**
  * Creates an error message for a JavaScript error thrown during
  * executeScript or executeAsyncScript.