diff --git a/doc/dev-docs/source/Reference.rst b/doc/dev-docs/source/Reference.rst
index a3b7828..5881d34 100644
--- a/doc/dev-docs/source/Reference.rst
+++ b/doc/dev-docs/source/Reference.rst
@@ -1,16 +1,16 @@
 Reference
 ---------
 
 .. doxygenclass:: muSpectre::SystemBase
 
 Doxygen index
--------------
+~~~~~~~~~~~~~
 
 .. doxygenindex::
    :project: µSpectre
 
 .. Doxygennamespace
    ----------------
 .. .. doxygennamespace:: muSpectre
       :project: µSpectre
       :outline: