diff --git a/acme/docs/conf.py b/acme/docs/conf.py
index 21a412ec0..7b243771f 100644
--- a/acme/docs/conf.py
+++ b/acme/docs/conf.py
@@ -35,6 +35,7 @@ extensions = [
     'sphinx.ext.todo',
     'sphinx.ext.coverage',
     'sphinx.ext.viewcode',
+    'sphinxcontrib.programoutput',
 ]
 
 # Add any paths that contain templates here, relative to this directory.
diff --git a/letsencrypt-compatibility-test/docs/conf.py b/letsencrypt-compatibility-test/docs/conf.py
index 3cd77fe0e..a118bedf1 100644
--- a/letsencrypt-compatibility-test/docs/conf.py
+++ b/letsencrypt-compatibility-test/docs/conf.py
@@ -35,6 +35,7 @@ extensions = [
     'sphinx.ext.todo',
     'sphinx.ext.coverage',
     'sphinx.ext.viewcode',
+    'repoze.sphinx.autointerface',
 ]
 
 # Add any paths that contain templates here, relative to this directory.