diff --git a/docs/conf.py b/docs/conf.py
index 8f608ab..b61c854 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -35,7 +35,8 @@
     'sphinx.ext.todo',
     'sphinx.ext.githubpages',
     'sphinx.ext.graphviz',
-    'piccolo_theme',    
+    'piccolo_theme',
+    'sphinx_copybutton',
     'exercise',
     'state_space',
     'specification',
diff --git a/requirements.txt b/requirements.txt
index 357693f..7f7a43b 100644
Binary files a/requirements.txt and b/requirements.txt differ