diff --git a/docsite/conf.py b/docsite/conf.py
index 95bc1fb8328..b300813b255 100644
--- a/docsite/conf.py
+++ b/docsite/conf.py
@@ -100,7 +100,7 @@ exclude_patterns = ['modules']
 # The name of the Pygments (syntax highlighting) style to use.
 pygments_style = 'sphinx'
 
-highlight_language = 'YAML'
+highlight_language = 'yaml'
 
 
 # Options for HTML output