diff --git a/gtk2_ardour/editor_sources.cc b/gtk2_ardour/editor_sources.cc
index f8b4d65b61..6ba481bec6 100644
--- a/gtk2_ardour/editor_sources.cc
+++ b/gtk2_ardour/editor_sources.cc
@@ -495,10 +495,17 @@ EditorSources::add_source (boost::shared_ptr<ARDOUR::Region> region)
 	 * if there's some other kind of source, we ignore it (for now)
 	 */
 	boost::shared_ptr<FileSource> fs = boost::dynamic_pointer_cast<FileSource> (region->source());
-	if (!fs || fs->empty()) {
+	if (!fs) {
 		return;
 	}
 
+	if (fs->empty()) {
+		/* MIDI sources are allowed to be empty */
+		if (!boost::dynamic_pointer_cast<MidiSource> (region->source())) {
+			return;
+		}
+	}
+
 	region->DropReferences.connect (remove_region_connections, MISSING_INVALIDATOR, boost::bind (&EditorSources::remove_weak_region, this, boost::weak_ptr<Region> (region)), gui_context());
 
 	TreeModel::Row row = *(_model->append());