diff --git a/doc/source/conf.py b/doc/source/conf.py
index 0fce986b91f720c52c393bd6c0cd617e430af4d4..8a2e022b56bc762d9eb5c1b27fe460a88ff57f36 100644
--- a/doc/source/conf.py
+++ b/doc/source/conf.py
@@ -138,7 +138,8 @@ latex_elements = {
 # (source start file, target name, title,
 #  author, documentclass [howto, manual, or own class]).
 latex_documents = [
-    (master_doc, 'Navigation_Toolbox.tex', 'Navigation\\_Toolbox Documentation',
+    (master_doc, 'Navigation_Toolbox.tex',
+     'Navigation\\_Toolbox Documentation',
      'Olivier J.N. Bertrand', 'manual'),
 ]