diff --git a/requirements.txt b/requirements.txt
index 2062d7b0..965e06e4 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -9,4 +9,3 @@ oslo.config>=2.1.0 # Apache-2.0
 oslo.i18n>=1.5.0 # Apache-2.0
 oslo.log>=1.8.0 # Apache-2.0
 oslo.utils>=2.0.0 # Apache-2.0
-python-memcached>=1.56
diff --git a/setup.cfg b/setup.cfg
index 96218625..7ede0496 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -28,6 +28,12 @@ packages =
 oslo.config.opts =
     oslo.cache = oslo_cache._opts:list_opts
 
+[extras]
+dogpile =
+  python-memcached>=1.56
+mongo =
+  pymongo>=3.0.2
+
 [pbr]
 warnerrors = true
 autodoc_tree_index_modules = True
diff --git a/test-requirements.txt b/test-requirements.txt
index 60409a49..8463ff93 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -6,6 +6,3 @@ mock>=1.2
 oslotest>=1.10.0 # Apache-2.0
 oslosphinx>=2.5.0 # Apache-2.0
 sphinx!=1.2.0,!=1.3b1,<1.3,>=1.1.2
-
-# Optional dogpile backend: MongoDB
-pymongo>=3.0.2
diff --git a/tox.ini b/tox.ini
index 2caa42d3..e3bc0d19 100644
--- a/tox.ini
+++ b/tox.ini
@@ -12,7 +12,8 @@ envlist = py34,py26,py27,pypy,pep8
 install_command = pip install -U {opts} {packages}
 setenv =
    VIRTUAL_ENV={envdir}
-deps = -r{toxinidir}/requirements.txt
+deps = .[dogpile]
+       .[mongo]
        -r{toxinidir}/test-requirements.txt
 commands = python setup.py testr --slowest --testr-args='{posargs}'