diff --git a/doc/conf.py b/doc/conf.py
index f560ae0b..fb94d404 100644
--- a/doc/conf.py
+++ b/doc/conf.py
@@ -20,6 +20,7 @@ import time
 # 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(1, os.path.abspath('../test-packages'))
 
 # -- General configuration -----------------------------------------------------
 
diff --git a/doc/requirements.txt b/doc/requirements.txt
new file mode 100644
index 00000000..3dd3d0df
--- /dev/null
+++ b/doc/requirements.txt
@@ -0,0 +1,3 @@
+# WARNING: those requirements are used only for readthedocs.org
+# they SHOULD NOT be used under normal conditions; use system package manager
+lxml
diff --git a/test-packages/dbus.py b/test-packages/dbus.py
new file mode 100644
index 00000000..a03885d1
--- /dev/null
+++ b/test-packages/dbus.py
@@ -0,0 +1,2 @@
+class DBusException(Exception):
+    pass