diff --git a/docs/source/conf.py b/docs/source/conf.py
index e28894f3b142447e19b5d7510b76236ab372c71c..5e6e2a4ba6548bcfa523a1d7b8c8be16d2894ac1 100644
--- a/docs/source/conf.py
+++ b/docs/source/conf.py
@@ -50,7 +50,7 @@ exclude_patterns = []
 # The theme to use for HTML and HTML Help pages.  See the documentation for
 # a list of builtin themes.
 #
-html_theme = 'sphinx-rtd-theme'
+html_theme = 'sphinx_rtd_theme'
 
 # Add any paths that contain custom static files (such as style sheets) here,
 # relative to this directory. They are copied after the builtin static files,