diff --git a/mitogen/master.py b/mitogen/master.py
index c3a52788..86909b32 100644
--- a/mitogen/master.py
+++ b/mitogen/master.py
@@ -584,9 +584,10 @@ class ModuleResponder(object):
                 pkg_present = None
 
             compressed = zlib.compress(source)
+            related = self._finder.find_related(fullname)
             self._router.route(
                 mitogen.core.Message.pickled(
-                    (pkg_present, path, compressed),
+                    (pkg_present, path, compressed, related),
                     dst_id=msg.src_id,
                     handle=msg.reply_to,
                 )