diff --git a/tox.ini b/tox.ini
index 5baaa46..8679f9f 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,6 +1,6 @@
 [tox]
 envlist =
-    py{27,34,35,36}-sphinx{13,14,15}
+    py{27,34,35,36}-sphinx{13,14,15,16}
     lint
     docs
 
@@ -17,6 +17,7 @@ setenv =
 deps = -r{toxinidir}/requirements.txt
     pytest
     mock
+    sphinx13: Sphinx<1.4
     sphinx14: Sphinx<1.5
     sphinx15: Sphinx<1.6
     sphinx16: Sphinx<1.7