diff --git a/libs/ardour/plugin_manager.cc b/libs/ardour/plugin_manager.cc
index 6bf51da994..458f7e1547 100644
--- a/libs/ardour/plugin_manager.cc
+++ b/libs/ardour/plugin_manager.cc
@@ -645,7 +645,6 @@ PluginManager::au_refresh (bool cache_only)
 	delete _au_plugin_info;
 	_au_plugin_info = AUPluginInfo::discover();
 
-	bool discover_at_start = Config->get_discover_audio_units ();
 	// disable automatic scan in case we crash
 	Config->set_discover_audio_units (false);
 	Config->save_state();
@@ -664,7 +663,7 @@ PluginManager::au_refresh (bool cache_only)
 	 */
 
 	// successful scan re-enabled automatic discovery
-	Config->set_discover_audio_units (discover_at_start);
+	Config->set_discover_audio_units (true);
 	Config->save_state();
 }