diff --git a/tox.ini b/tox.ini
index 1710b45f..eebc9bfa 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,43 +1,83 @@
 [tox]
 envlist=black,flake8,mypy,py3
 
 [testenv]
 extras =
   testing
 deps =
   pytest-cov
   dev: ipdb
 passenv =
   SWH_CASSANDRA_BIN
   SWH_CASSANDRA_LOG
   JAVA_HOME
 commands =
   pytest \
     !slow: --hypothesis-profile=fast \
     slow:  --hypothesis-profile=slow \
          --cov={envsitepackagesdir}/swh/storage \
          {envsitepackagesdir}/swh/storage \
          --doctest-modules \
          --cov-branch {posargs}
 
 [testenv:black]
 skip_install = true
 deps =
   black==19.10b0
 commands =
   {envpython} -m black --check swh
 
 [testenv:flake8]
 skip_install = true
 deps =
   flake8
 commands =
   {envpython} -m flake8
 
 [testenv:mypy]
 extras =
   testing
 deps =
   mypy
 commands =
   mypy swh
+
+# build documentation outside swh-environment using the current
+# git HEAD of swh-docs, is executed on CI for each diff to prevent
+# breaking doc build
+[testenv:sphinx]
+whitelist_externals = make
+usedevelop = true
+extras =
+  testing
+deps =
+  # fetch and install swh-docs in develop mode
+  -e git+https://forge.softwareheritage.org/source/swh-docs#egg=swh.docs
+  pifpaf
+
+setenv =
+  SWH_PACKAGE_DOC_TOX_BUILD = 1
+  # turn warnings into errors
+  SPHINXOPTS = -W
+commands =
+  {envpython} -m pifpaf run postgresql -- make -I ../.tox/sphinx/src/swh-docs/swh/ -C docs
+
+
+# build documentation only inside swh-environment using local state
+# of swh-docs package
+[testenv:sphinx-dev]
+whitelist_externals = make
+usedevelop = true
+extras =
+  testing
+deps =
+  # install swh-docs in develop mode
+  -e ../swh-docs
+  pifpaf
+
+setenv =
+  SWH_PACKAGE_DOC_TOX_BUILD = 1
+  # turn warnings into errors
+  SPHINXOPTS = -W
+commands =
+  {envpython} -m pifpaf run postgresql -- make -I ../.tox/sphinx-dev/src/swh-docs/swh/ -C docs