diff --git a/libs/ardour/control_protocol_manager.cc b/libs/ardour/control_protocol_manager.cc
index 18e7e177d6..b97c89b809 100644
--- a/libs/ardour/control_protocol_manager.cc
+++ b/libs/ardour/control_protocol_manager.cc
@@ -226,6 +226,7 @@ ControlProtocolManager::teardown (ControlProtocolInfo& cpi)
 	delete cpi.state;
 	cpi.state = 0;
 	delete (Glib::Module*)cpi.descriptor->module;
+	cpi.descriptor->module = 0;
 
 	ProtocolStatusChange (&cpi);