diff --git a/CHANGES.rst b/CHANGES.rst
index c9d0d2c..bf3c4a9 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -14,7 +14,9 @@ New features:
 
 Bug fixes:
 
-- *add item here*
+- Make sure the effects of the robotframework REMOTE_LIBRARY_ROBOT_TESTING fixture
+  are not accidentally removed when tearing down the PLONE_APP_DISCUSSION_ROBOT_TESTING fixture.
+  [davisagli]
 
 
 3.0.3 (2017-08-27)
diff --git a/plone/app/discussion/testing.py b/plone/app/discussion/testing.py
index 4280a6e..a7c439a 100644
--- a/plone/app/discussion/testing.py
+++ b/plone/app/discussion/testing.py
@@ -98,6 +98,11 @@ class PloneAppDiscussion(PloneSandboxLayer):
 
 class PloneAppDiscussionRobot(PloneAppDiscussion):
 
+    defaultBases = (
+        PLONE_APP_CONTENTTYPES_FIXTURE,
+        REMOTE_LIBRARY_ROBOT_TESTING,
+    )
+
     def setUpPloneSite(self, portal):
         registry = queryUtility(IRegistry)
         settings = registry.forInterface(IDiscussionSettings)
@@ -113,9 +118,6 @@ PLONE_APP_DISCUSSION_FUNCTIONAL_TESTING = FunctionalTesting(
     bases=(PLONE_APP_DISCUSSION_FIXTURE,),
     name='PloneAppDiscussion:Functional')
 PLONE_APP_DISCUSSION_ROBOT_TESTING = FunctionalTesting(
-    bases=(
-        PLONE_APP_DISCUSSION_ROBOT_FIXTURE,
-        REMOTE_LIBRARY_ROBOT_TESTING
-    ),
+    bases=(PLONE_APP_DISCUSSION_ROBOT_FIXTURE,),
     name='PloneAppDiscussion:Robot'
 )