diff --git a/setup.py b/setup.py
index 692313f..e69ffee 100644
--- a/setup.py
+++ b/setup.py
@@ -290,7 +290,7 @@
             "doc8",
             "pyenchant >= 1.6.11",
             "readme_renderer >= 16.0",
-            "sphinx != 1.6.1, != 1.6.2, != 1.6.3",
+            "sphinx != 1.6.1, != 1.6.2, != 1.6.3, != 1.6.4",
             "sphinx_rtd_theme",
             "sphinxcontrib-spelling",
         ],