diff --git a/tox.ini b/tox.ini
index 83ba212..e55d322 100644
--- a/tox.ini
+++ b/tox.ini
@@ -27,13 +27,13 @@
            python -m unittest discover libcloud/test
 
 [testenv:docs]
-deps = sphinx
-       pysphere
+deps = pysphere
        backports.ssl_match_hostname
        lockfile
        rstcheck
 changedir = docs
-commands = rstcheck --report warning ../CHANGES.rst
+commands = pip install sphinx~=1.6.0
+           rstcheck --report warning ../CHANGES.rst
            python ../contrib/generate_provider_feature_matrix_table.py
            sphinx-apidoc -d 4 ../libcloud/ -o apidocs/
            /bin/bash -c "ls apidocs/modules.rst && (grep orphan apidocs/modules.rst || sed -i '1i :orphan:\n' apidocs/modules.rst) || (exit 0)"
@@ -42,13 +42,13 @@
 [testenv:docs-travis]
 # Note: We don't build API docs on Travis since it causes build failures because
 # those API docs files are not included anywhere.
-deps = sphinx
-       pysphere
+deps = pysphere
        backports.ssl_match_hostname
        lockfile
        rstcheck
 changedir = docs
-commands = rstcheck --report warning ../CHANGES.rst
+commands = pip install sphinx~=1.6.0
+           rstcheck --report warning ../CHANGES.rst
            python ../contrib/generate_provider_feature_matrix_table.py
            /bin/bash -c "ls apidocs/modules.rst && (grep orphan apidocs/modules.rst || sed -i '1i :orphan:\n' apidocs/modules.rst) || (exit 0)"
            sphinx-build -W -b html -d {envtmpdir}/doctrees . _build/html