diff --git a/doc/maintainers.rst b/doc/maintainers.rst
index 6370114fa1734753841affc0db6f97d85466ebe5..eee2adc9921f8f63e34e7d712ae6f1699b4317db 100644
--- a/doc/maintainers.rst
+++ b/doc/maintainers.rst
@@ -70,7 +70,7 @@ Installing additional packages
 In order to install additional packages in a Toolbox environment, one should
 run the following commands:
 
-.. code::shell
+.. code:: shell
 
     cd <PROPOSAL_PATH>/usr/Software/
     source envs/toolbox_<IDENTIFIER>/bin/activate