diff --git a/doc/requirements.txt b/doc/requirements.txt
index 280af85b..f9e6b367 100644
--- a/doc/requirements.txt
+++ b/doc/requirements.txt
@@ -2,11 +2,7 @@
 # of appearance. Changing the order has an impact on the overall integration
 # process, which may cause wedges in the gate later.
 sphinx>=1.6.2 # BSD
-sphinx_rtd_theme==0.2.4
+sphinx_rtd_theme
 reno>=2.5.0 # Apache-2.0
 plantuml
 
-# NOTE(fmontei): The requirement below is only included because readthedocs
-# depends on it to work, since it only takes in one requirements file.
-oslo.config!=4.3.0,!=4.4.0,>=5.2.0 # Apache-2.0
-oslo.policy>=1.33.1 # Apache-2.0
diff --git a/doc/source/conf.py b/doc/source/conf.py
index 372a92ff..399dc0a6 100644
--- a/doc/source/conf.py
+++ b/doc/source/conf.py
@@ -18,8 +18,13 @@
 #
 import os
 import sys
-sys.path.insert(0, os.path.abspath('.'))
+
+# If extensions (or modules to document with autodoc) are in another directory,
+# add these directories to sys.path here. If the directory is relative to the
+# documentation root, use os.path.abspath to make it absolute, like shown here.
+sys.path.insert(0, os.path.abspath('../../'))
 sys.path.insert(0, os.path.abspath('../'))
+sys.path.insert(0, os.path.abspath('./'))
 
 # -- General configuration ------------------------------------------------
 
diff --git a/doc/source/images/architecture-pegleg.png b/doc/source/images/architecture-pegleg.png
index ed0a368d..85428fbe 100644
Binary files a/doc/source/images/architecture-pegleg.png and b/doc/source/images/architecture-pegleg.png differ
diff --git a/doc/source/images/architecture.png b/doc/source/images/architecture.png
index 1ba9361d..225a7948 100644
Binary files a/doc/source/images/architecture.png and b/doc/source/images/architecture.png differ