diff --git a/doc/conf.py b/doc/conf.py
index 01c3379cfd56dc09d4600a48501c383b5f2a03a9..1850d0d29fbf591a03a12a1fac5c2851fbf08a60 100644
--- a/doc/conf.py
+++ b/doc/conf.py
@@ -73,6 +73,11 @@ def patched_make_field(self, types, domain, items, env=None):
 
 TypedField.make_field = patched_make_field
 
+# This shouldn't be needed, as using a virtualenv + setup.py should set up the
+# sys.path correctly. However that seems to be half broken on ReadTheDocs, so
+# manually set it here
+sys.path.insert(0, os.path.abspath('../'))
+
 # -- General configuration ------------------------------------------------
 
 # If your documentation needs a minimal Sphinx version, state it here.