diff --git a/gtk2_ardour/plugin_manager_ui.cc b/gtk2_ardour/plugin_manager_ui.cc
index 14c23b54b1..26a34b4323 100644
--- a/gtk2_ardour/plugin_manager_ui.cc
+++ b/gtk2_ardour/plugin_manager_ui.cc
@@ -240,9 +240,19 @@ PluginManagerUI::~PluginManagerUI ()
 }
 
 void
-PluginManagerUI::on_show ()
+PluginManagerUI::PluginCount::set (PluginScanLogEntry const& psle)
 {
-	ArdourWindow::on_show ();
+	++total;
+	if (!psle.recent ()) {
+		++stale;
+		return;
+	}
+	PluginScanLogEntry::PluginScanResult sr = psle.result ();
+	if ((int)sr & (PluginScanLogEntry::TimeOut | PluginScanLogEntry::Updated | PluginScanLogEntry::New)) {
+		++ndscn;
+	} else if (sr != PluginScanLogEntry::OK) {
+		++error;
+	}
 }
 
 static std::string
@@ -329,35 +339,6 @@ PluginManagerUI::refill ()
 
 	bool rescan_err = false;
 	bool have_stale = false;
-
-	struct PluginCount {
-		PluginCount ()
-			: total (0)
-			, error (0)
-			, stale (0)
-			, ndscn (0)
-		{}
-
-		void set (PluginScanLogEntry const& psle) {
-			++total;
-			if (!psle.recent ()) {
-				++stale;
-				return;
-			}
-			PluginScanLogEntry::PluginScanResult sr = psle.result ();
-			if ((int)sr & (PluginScanLogEntry::TimeOut | PluginScanLogEntry::Updated | PluginScanLogEntry::New)) {
-				++ndscn;
-			} else if (sr != PluginScanLogEntry::OK) {
-				++error;
-			}
-		}
-
-		unsigned int total;
-		unsigned int error;
-		unsigned int stale;
-		unsigned int ndscn;
-	};
-
 	std::map<PluginType, PluginCount> plugin_count;
 
 	std::vector<boost::shared_ptr<PluginScanLogEntry> > psl;
diff --git a/gtk2_ardour/plugin_manager_ui.h b/gtk2_ardour/plugin_manager_ui.h
index 057604daa1..3009ea6e1a 100644
--- a/gtk2_ardour/plugin_manager_ui.h
+++ b/gtk2_ardour/plugin_manager_ui.h
@@ -44,7 +44,6 @@ public:
 
 private:
 	void refill ();
-	void on_show ();
 	void selection_changed ();
 	void blacklist_changed (std::string const&);
 	void favorite_changed (std::string const&);
@@ -61,6 +60,22 @@ private:
 
 	void plugin_status_changed (ARDOUR::PluginType, std::string, ARDOUR::PluginManager::PluginStatusType);
 
+	struct PluginCount {
+		PluginCount ()
+			: total (0)
+			, error (0)
+			, stale (0)
+			, ndscn (0)
+		{}
+
+		void set (ARDOUR::PluginScanLogEntry const& psle);
+
+		unsigned int total;
+		unsigned int error;
+		unsigned int stale;
+		unsigned int ndscn;
+	};
+
 	struct PluginColumns : public Gtk::TreeModel::ColumnRecord {
 		PluginColumns () {
 			add (status);