--- a/ansible/roles/docker-rbweb/tasks/main.yml
+++ b/ansible/roles/docker-rbweb/tasks/main.yml
@@ -18,16 +18,18 @@
 - name: Install Djblets and Review Board
   command: /venv/bin/python setup.py install
            chdir=/version-control-tools/reviewboard-fork/{{ item }}
   with_items:
     - djblets
     - reviewboard
   tags:
     - docker-reviewboard-refresh
+  environment:
+    MOZREVIEW_DEV: 1
 
 - name: Install python libraries
   command: /venv/bin/python setup.py install chdir=/version-control-tools/pylib/{{ item }}
   with_items:
     - mozautomation
 
 - name: Build mozreview extension
   command: /venv/bin/python setup.py bdist_egg chdir=/version-control-tools/pylib/mozreview

--- a/testing/vcttesting/mozreview.py
+++ b/testing/vcttesting/mozreview.py
@@ -49,16 +49,19 @@ logger = logging.getLogger(__name__)
 
 WATCHMAN = None
 for path in os.environ['PATH'].split(':'):
     c = os.path.join(path, 'watchman')
     if os.path.exists(c):
         WATCHMAN = c
         break
 
+# Allow reviewboard-fork to easily detect when running within the dev env.
+os.putenv('MOZREVIEW_DEV', '1')
+
 
 class MozReview(object):
     """Interface to MozService service.
 
     This class can be used to create and control MozReview instances.
     """
 
     def __init__(self, path, web_image=None, hgrb_image=None,