diff --git a/sphinx/__init__.py b/sphinx/__init__.py
index cd62435d9..e2102e393 100644
--- a/sphinx/__init__.py
+++ b/sphinx/__init__.py
@@ -54,6 +54,7 @@ def init_builder(buildername, srcdirname, outdirname, doctreedir,
                            status_stream=status, warning_stream=warning,
                            events=events, config=config, freshenv=freshenv)
     events.emit('builder-created', builder)
+    return builder
 
 
 def usage(argv, msg=None):