diff --git a/testing/marionette/client/marionette_driver/marionette.py b/testing/marionette/client/marionette_driver/marionette.py
index b9123cac1122..c153dcbd306c 100644
--- a/testing/marionette/client/marionette_driver/marionette.py
+++ b/testing/marionette/client/marionette_driver/marionette.py
@@ -207,6 +207,10 @@ class HTMLElement(object):
     def __eq__(self, other_element):
         return self.id == other_element.id
 
+    def __hash__(self):
+        # pylint --py3k: W1641
+        return hash(self.id)
+
     def find_element(self, method, target):
         """Returns an ``HTMLElement`` instance that matches the specified
         method and target, relative to the current element.
diff --git a/testing/marionette/client/marionette_driver/transport.py b/testing/marionette/client/marionette_driver/transport.py
index 679b14562fd7..1cdc777d9d25 100644
--- a/testing/marionette/client/marionette_driver/transport.py
+++ b/testing/marionette/client/marionette_driver/transport.py
@@ -36,6 +36,10 @@ class Message(object):
     def __ne__(self, other):
         return not self.__eq__(other)
 
+    def __hash__(self):
+        # pylint --py3k: W1641
+        return hash(self.id)
+
 
 class Command(Message):
     TYPE = 0
diff --git a/testing/mozbase/mozinfo/mozinfo/string_version.py b/testing/mozbase/mozinfo/mozinfo/string_version.py
index 02739920c260..b1b434c49a53 100644
--- a/testing/mozbase/mozinfo/mozinfo/string_version.py
+++ b/testing/mozbase/mozinfo/mozinfo/string_version.py
@@ -53,6 +53,10 @@ class StringVersion(six.text_type):
         if self.version > other.version:
             return 1
 
+    def __hash__(self):
+        # pylint --py3k: W1641
+        return hash(self.version)
+
     # operator overloads
     def __eq__(self, other):
         return self._cmp(other) == 0
diff --git a/testing/mozbase/mozprofile/mozprofile/permissions.py b/testing/mozbase/mozprofile/mozprofile/permissions.py
index 362491c98c71..5d456bf93fa9 100644
--- a/testing/mozbase/mozprofile/mozprofile/permissions.py
+++ b/testing/mozbase/mozprofile/mozprofile/permissions.py
@@ -110,6 +110,10 @@ class Location(object):
 
     __eq__ = isEqual
 
+    def __hash__(self):
+        # pylint --py3k: W1641
+        return hash(tuple(getattr(attr) for attr in self.attrs))
+
     def url(self):
         return "%s://%s:%s" % (self.scheme, self.host, self.port)
 
diff --git a/testing/mozharness/external_tools/tooltool.py b/testing/mozharness/external_tools/tooltool.py
index 3747e57e95aa..7fa40e5880db 100755
--- a/testing/mozharness/external_tools/tooltool.py
+++ b/testing/mozharness/external_tools/tooltool.py
@@ -497,6 +497,19 @@ class FileRecord(object):
     def __ne__(self, other):
         return not self.__eq__(other)
 
+    def __hash__(self):
+        # pylint --py3k: W1641
+        return hash(
+            (
+                self.filename,
+                self.size,
+                self.digest,
+                self.algorithm,
+                self.version,
+                self.visibility,
+            )
+        )
+
     def __str__(self):
         return repr(self)
 
@@ -669,6 +682,10 @@ class Manifest(object):
     def __ne__(self, other):
         return not self.__eq__(other)
 
+    def __hash__(self):
+        # pylint --py3k: W1641
+        return hash(tuple(sorted((fr.filename, fr) for fr in self.file_records)))
+
     def __deepcopy__(self, memo):
         # This is required for a deep copy
         return Manifest(self.file_records[:])