diff --git a/doc/source/conf.py b/doc/source/conf.py
index 76da420159a6d79f912e91921fc68e5a6524c15d..dcf58561c542fe7573447d69e5515a99dd1c7fd7 100644
--- a/doc/source/conf.py
+++ b/doc/source/conf.py
@@ -41,7 +41,6 @@ release = ''
 extensions = [
     'sphinx.ext.imgmath',
     'sphinx.ext.todo',
-    'sphinxcontrib.bibtex',
     'breathe',
     # Currently, graphviz has no option to deal with large figures
     'modifiedgraphviz',