diff --git a/libs/pbd/base_ui.cc b/libs/pbd/base_ui.cc
index 6c9a095d6d..83df2b76b5 100644
--- a/libs/pbd/base_ui.cc
+++ b/libs/pbd/base_ui.cc
@@ -119,12 +119,11 @@ BaseUI::run ()
 
 	m_context = MainContext::create();
 	_main_loop = MainLoop::create (m_context);
+	attach_request_source ();
 
 	Glib::Threads::Mutex::Lock lm (_run_lock);
 	_run_loop_thread = PBD::Thread::create (boost::bind (&BaseUI::main_thread, this));
 	_running.wait (_run_lock);
-
-	attach_request_source ();
 }
 
 void
diff --git a/libs/pbd/pbd/base_ui.h b/libs/pbd/pbd/base_ui.h
index 27bdb71644..fff6f5da84 100644
--- a/libs/pbd/pbd/base_ui.h
+++ b/libs/pbd/pbd/base_ui.h
@@ -53,7 +53,7 @@ class LIBPBD_API BaseUI : public sigc::trackable, public PBD::EventLoop
 	BaseUI* base_instance() { return base_ui_instance; }
 
 	Glib::RefPtr<Glib::MainLoop> main_loop() const { return _main_loop; }
-	bool caller_is_self () const { assert (_run_loop_thread); return _run_loop_thread->caller_is_self (); }
+	bool caller_is_self () const { return _run_loop_thread ? _run_loop_thread->caller_is_self () : true; }
 
 	bool ok() const { return _ok; }