diff --git a/docs/conf.py b/docs/conf.py
index eb7f4b2..4f47c3b 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -95,7 +95,7 @@ pygments_style = 'sphinx'
 
 # -- Options for HTML output ----------------------------------------------
 
-if not os.environ.get('READTHEDOCS', None) == 'True':
+if os.environ.get('READTHEDOCS', None) == 'True':
     import sphinx_rtd_theme
     html_theme = "sphinx_rtd_theme"
     html_theme_path = [sphinx_rtd_theme.get_html_theme_path()]