diff --git a/doc/requirements.txt b/doc/requirements.txt
new file mode 100644
index 000000000..4bf57b61d
--- /dev/null
+++ b/doc/requirements.txt
@@ -0,0 +1,5 @@
+# documentation
+sphinx>=2.0.0,!=2.1.0 # BSD
+os-api-ref>=1.4.0 # Apache-2.0
+reno>=3.1.0 # Apache-2.0
+openstackdocstheme>=2.2.1 # Apache-2.0
diff --git a/test-requirements.txt b/test-requirements.txt
index 756f72556..ff03dd92e 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -22,9 +22,4 @@ testscenarios>=0.4 # Apache-2.0/BSD
 testtools>=2.2.0 # MIT
 tempest>=17.1.0 # Apache-2.0
 
-# documentation
 doc8>=0.6.0 # Apache-2.0
-sphinx>=2.0.0,!=2.1.0 # BSD
-os-api-ref>=1.4.0 # Apache-2.0
-reno>=3.1.0 # Apache-2.0
-openstackdocstheme>=2.2.1 # Apache-2.0
diff --git a/tox.ini b/tox.ini
index d6cb63869..22a2a0d3c 100644
--- a/tox.ini
+++ b/tox.ini
@@ -65,6 +65,8 @@ commands =
   {[testenv:checkniceness]commands}
 
 [testenv:docs]
+deps = -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
+       -r{toxinidir}/doc/requirements.txt
 description = Builds api-ref, api-guide, releasenotes and devdocs
 commands =
   {[testenv:devdocs]commands}
@@ -72,6 +74,7 @@ commands =
   {[testenv:releasenotes]commands}
 
 [testenv:pdf-docs]
+deps = {[testenv:docs]deps}
 envdir = {toxworkdir}/docs
 whitelist_externals =
   make
@@ -82,6 +85,7 @@ commands =
   make -C doc/build/pdf
 
 [testenv:api-ref]
+deps = {[testenv:docs]deps}
 description = Called from CI scripts to test and publish the API Ref
 commands =
   rm -rf api-ref/build
@@ -90,6 +94,7 @@ commands =
     api-ref/source api-ref/build/html
 
 [testenv:releasenotes]
+deps = {[testenv:docs]deps}
 description = Called from CI script to test and publish the Release Notes
 commands =
   rm -rf releasenotes/build
@@ -97,6 +102,7 @@ commands =
     releasenotes/source releasenotes/build/html
 
 [testenv:devdocs]
+deps = {[testenv:docs]deps}
 description = Builds developer documentation
 commands =
   rm -rf doc/build doc/source/contributor/api