--- a/testing/vcttesting/bugzilla/__init__.py
+++ b/testing/vcttesting/bugzilla/__init__.py
@@ -1,16 +1,15 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 import base64
 
 import bugsy
-import mechanize
 import xmlrpclib
 import yaml
 
 from mozautomation.bugzilla_transports import bugzilla_transport
 
 
 def create_xmlrpc_proxy(url, username, password):
     """Obtain an XMLRPC proxy to the Bugzilla service."""
@@ -124,16 +123,19 @@ class Bugzilla(object):
 
     def update_user_login_denied_text(self, email, text):
         return self.proxy.User.update({
             'names': [email],
             'login_denied_text': text,
         })
 
     def create_login_cookie(self):
+        # Delay import to facilitate module use in limited virtualenvs.
+        import mechanize
+
         # We simulate a browser's HTML interaction with Bugzilla to obtain a
         # login cookie. Is there a better way?
         br = mechanize.Browser()
         url = self.base_url + '/'
         br.set_handle_robots(False)
         br.open(url)
         br.select_form(nr=0)
         br.form['Bugzilla_login'] = self.username

--- a/testing/vcttesting/bugzilla/mach_commands.py
+++ b/testing/vcttesting/bugzilla/mach_commands.py
@@ -6,29 +6,32 @@ import os
 
 from mach.decorators import (
     CommandArgument,
     CommandProvider,
     Command,
 )
 
 from vcttesting.bugzilla import Bugzilla
-from vcttesting.mozreview import MozReview
+
 
 @CommandProvider
 class BugzillaCommands(object):
     def __init__(self, context):
         if 'BUGZILLA_URL' in os.environ:
             self.base_url = os.environ['BUGZILLA_URL']
             username = os.environ['BUGZILLA_USERNAME']
             password = os.environ['BUGZILLA_PASSWORD']
 
             self.b = Bugzilla(self.base_url, username=username, password=password)
 
         elif 'MOZREVIEW_HOME' in os.environ:
+            # Delay import to facilitate module use in limited virtualenvs.
+            from vcttesting.mozreview import MozReview
+
             mr = MozReview(os.environ['MOZREVIEW_HOME'])
             username = os.environ.get('BUGZILLA_USERNAME')
             password = os.environ.get('BUGZILLA_PASSWORD')
 
             self.b = mr.get_bugzilla(username=username, password=password)
 
         else:
             raise Exception('Do not know which Bugzilla instance to talk to. '

--- a/testing/vcttesting/util.py
+++ b/testing/vcttesting/util.py
@@ -4,19 +4,16 @@
 
 from __future__ import absolute_import, unicode_literals
 
 import os
 import socket
 import time
 
 import concurrent.futures as futures
-from kafka.client import KafkaClient
-import kombu
-import paramiko
 import requests
 
 
 HERE = os.path.abspath(os.path.dirname(__file__))
 ROOT = os.path.normpath(os.path.join(HERE, '..', '..'))
 
 
 def get_available_port():
@@ -53,16 +50,18 @@ def wait_for_http(host, port, path='', t
         if time.time() - start > timeout:
             raise Exception('Timeout reached waiting for HTTP')
 
         time.sleep(0.1)
 
 
 def wait_for_amqp(hostname, port, userid, password, ssl=False, timeout=60,
                   extra_check_fn=None):
+    # Delay import to facilitate module use in limited virtualenvs.
+    import kombu
     c = kombu.Connection(hostname=hostname, port=port, userid=userid,
             password=password, ssl=ssl)
 
     start = time.time()
 
     while True:
         try:
             c.connection
@@ -74,23 +73,25 @@ def wait_for_amqp(hostname, port, userid
             extra_check_fn()
 
         if time.time() - start > timeout:
             raise Exception('Timeout reached waiting for AMQP')
 
         time.sleep(0.1)
 
 
-class IgnoreHostKeyPolicy(paramiko.MissingHostKeyPolicy):
-    def missing_host_key(self, client, hostname, key):
-        return
-
-
 def wait_for_ssh(hostname, port, timeout=60, extra_check_fn=None):
     """Wait for an SSH server to start on the specified host and port."""
+    # Delay import to facilitate module use in limited virtualenvs.
+    import paramiko
+
+    class IgnoreHostKeyPolicy(paramiko.MissingHostKeyPolicy):
+        def missing_host_key(self, client, hostname, key):
+            return
+
     start = time.time()
 
     while True:
         client = paramiko.SSHClient()
         client.set_missing_host_key_policy(IgnoreHostKeyPolicy())
         try:
             client.connect(hostname, port=port, timeout=0.1, allow_agent=False,
                            look_for_keys=False)
@@ -110,32 +111,38 @@ def wait_for_ssh(hostname, port, timeout
         if time.time() - start > timeout:
             raise Exception('Timeout reached waiting for SSH')
 
         time.sleep(0.1)
 
 
 def wait_for_kafka(hostport, timeout=60):
     """Wait for Kafka to start responding on the specified host:port string."""
+    # Delay import to facilitate module use in limited virtualenvs.
+    from kafka.client import KafkaClient
+
     start = time.time()
     while True:
         try:
             KafkaClient(hostport, client_id=b'dummy', timeout=1)
             return
         except Exception:
             pass
 
         if time.time() - start > timeout:
             raise Exception('Timeout reached waiting for Kafka')
 
         time.sleep(0.1)
 
 
 def wait_for_kafka_topic(hostport, topic, timeout=60):
     """Wait for a Kafka topic to become available."""
+    # Delay import to facilitate module use in limited virtualenvs.
+    from kafka.client import KafkaClient
+
     start = time.time()
     client = KafkaClient(hostport, client_id=b'dummy', timeout=1)
     while not client.has_metadata_for_topic(topic):
         if time.time() - start > timeout:
             raise Exception('timeout reached waiting for topic')
 
         time.sleep(0.1)
         client.load_metadata_for_topics()