diff --git a/libs/surfaces/osc/osc.cc b/libs/surfaces/osc/osc.cc
index 9eb60147f43..ac5ff8e6d6e 100644
--- a/libs/surfaces/osc/osc.cc
+++ b/libs/surfaces/osc/osc.cc
@@ -2883,32 +2883,12 @@ OSC::_sel_plugin (int id, lo_address addr)
 			return 1;
 		}
 
-		/* find out how many plugins we have */
-		sur->plugins.clear();
-		for (int nplugs = 0; true; ++nplugs) {
-			std::shared_ptr<Processor> proc = r->nth_plugin (nplugs);
-			if (!proc) {
-				break;
-			}
-			if (!r->nth_plugin(nplugs)->display_to_user()) {
-				continue;
-			}
-#ifdef MIXBUS
-			/* need to check for mixbus channel strips (and exclude them) */
-			std::shared_ptr<PluginInsert> pi = std::dynamic_pointer_cast<PluginInsert>(proc);
-			if (pi && pi->is_channelstrip()) {
-				continue;
-			}
-#endif
-			sur->plugins.push_back (nplugs);
-		}
-
 		// limit plugin_id to actual plugins
 		if (sur->plugins.size() < 1) {
 			sur->plugin_id = 0;
 			sur->plug_page = 1;
 			if (sur->sel_obs) {
-				sur->sel_obs->set_plugin_id(-1, 1);
+				sur->sel_obs->set_plugin_id(0, 1);
 			}
 			return 0;
 		} else if (id < 1) {
@@ -2944,7 +2924,7 @@ OSC::_sel_plugin (int id, lo_address addr)
 		sur->plug_page = 1;
 
 		if (sur->sel_obs) {
-			sur->sel_obs->set_plugin_id(sur->plugins[sur->plugin_id - 1], sur->plug_page);
+			sur->sel_obs->set_plugin_id(sur->plugin_id, sur->plug_page);
 		}
 		return 0;
 	}
@@ -4760,11 +4740,36 @@ OSC::_strip_select2 (std::shared_ptr<Stripable> s, OSCSurface *sur, lo_address a
 		_select = s;
 	}
 	if (!s) {
+		sur->plugins.clear();
 		return 0;
 	}
 	if (s != old_sel) {
 		sur->select = s;
 	}
+
+	/* Create list of user-visible plugins (into which piid indexes) */
+	sur->plugins.clear();
+	std::shared_ptr<Route> r = std::dynamic_pointer_cast<Route>(s);
+	if (r) {
+		for (int nplugs = 0; true; ++nplugs) {
+			std::shared_ptr<Processor> proc = r->nth_plugin (nplugs);
+			if (!proc) {
+				break;
+			}
+			if (!r->nth_plugin(nplugs)->display_to_user()) {
+				continue;
+			}
+#ifdef MIXBUS
+			/* need to check for mixbus channel strips (and exclude them) */
+			std::shared_ptr<PluginInsert> pi = std::dynamic_pointer_cast<PluginInsert>(proc);
+			if (pi && pi->is_channelstrip()) {
+				continue;
+			}
+#endif
+			sur->plugins.push_back (nplugs);
+		}
+	}
+
 	bool sends;
 	uint32_t nsends  = 0;
 	do {
@@ -4807,7 +4812,6 @@ OSC::_strip_select2 (std::shared_ptr<Stripable> s, OSCSurface *sur, lo_address a
 	}
 	// need to set monitor for processor changed signal (for paging)
 	string address = lo_address_get_url (addr);
-	std::shared_ptr<Route> r = std::dynamic_pointer_cast<Route>(s);
 	if (r) {
 		r->processors_changed.connect  (sur->proc_connection, MISSING_INVALIDATOR, boost::bind (&OSC::processor_changed, this, address), this);
 		_sel_plugin (sur->plugin_id, addr);
diff --git a/libs/surfaces/osc/osc_select_observer.cc b/libs/surfaces/osc/osc_select_observer.cc
index a965b2f322c..686175f2348 100644
--- a/libs/surfaces/osc/osc_select_observer.cc
+++ b/libs/surfaces/osc/osc_select_observer.cc
@@ -77,9 +77,9 @@ OSCSelectObserver::OSCSelectObserver (OSC& o, ARDOUR::Session& s, ArdourSurface:
 	plug_size = plug_page_size;
 	plug_page = sur->plug_page;
 	if (sur->plugins.size () > 0) {
-		plug_id = sur->plugins[sur->plugin_id - 1];
+		selected_piid = sur->plugin_id;
 	} else {
-		plug_id = -1;
+		selected_piid = 0;
 	}
 	_group_sharing[15] = 1;
 	refresh_strip (sur->select, sur->nsends, gainmode, true);
@@ -441,7 +441,7 @@ OSCSelectObserver::send_end ()
 void
 OSCSelectObserver::set_plugin_id (int id, uint32_t page)
 {
-	plug_id = id;
+	selected_piid = id;
 	plug_page = page;
 	renew_plugin ();
 }
@@ -469,7 +469,7 @@ OSCSelectObserver::renew_plugin () {
 void
 OSCSelectObserver::plugin_init()
 {
-	if (plug_id < 0) {
+	if (!selected_piid) {
 		plugin_end ();
 		return;
 	}
@@ -480,12 +480,14 @@ OSCSelectObserver::plugin_init()
 	}
 
 	// we have a plugin number now get the processor
-	std::shared_ptr<Processor> proc = r->nth_plugin (plug_id);
+	std::shared_ptr<Processor> proc = r->nth_plugin (sur->plugins[selected_piid - 1]);
 	std::shared_ptr<PluginInsert> pi;
 	if (!(pi = std::dynamic_pointer_cast<PluginInsert>(proc))) {
 		plugin_end ();
 		return;
 	}
+	_osc.float_message (X_("/select/plugin"), selected_piid, addr);
+
 	std::shared_ptr<ARDOUR::Plugin> pip = pi->plugin();
 	// we have a plugin we can ask if it is activated
 	proc->ActiveChanged.connect (plugin_connections, MISSING_INVALIDATOR, boost::bind (&OSCSelectObserver::plug_enable, this, X_("/select/plugin/activate"), proc), OSC::instance());
@@ -558,6 +560,7 @@ void
 OSCSelectObserver::plugin_end ()
 {
 	plugin_connections.drop_connections ();
+	_osc.float_message (X_("/select/plugin"), 0, addr);
 	_osc.float_message (X_("/select/plugin/activate"), 0, addr);
 	_osc.text_message (X_("/select/plugin/name"), " ", addr);
 	for (uint32_t i = 1; i <= plug_size; i++) {
diff --git a/libs/surfaces/osc/osc_select_observer.h b/libs/surfaces/osc/osc_select_observer.h
index 171a985ddc6..30ff9978335 100644
--- a/libs/surfaces/osc/osc_select_observer.h
+++ b/libs/surfaces/osc/osc_select_observer.h
@@ -89,7 +89,7 @@ class OSCSelectObserver
 	uint32_t nplug_params;
 	uint32_t plug_page_size;
 	uint32_t plug_page;
-	int plug_id;
+	uint32_t selected_piid;
 	uint32_t plug_size;
 	std::vector<int> plug_params;
 	int eq_bands;