diff --git a/gtk2_ardour/port_matrix.cc b/gtk2_ardour/port_matrix.cc
index 8db2dad475..0fbbc03fb0 100644
--- a/gtk2_ardour/port_matrix.cc
+++ b/gtk2_ardour/port_matrix.cc
@@ -1009,10 +1009,10 @@ PortMatrix::update_tab_highlighting ()
 			string c = label->get_label ();
 			if (c.length() && c[0] == '<' && !has_connection) {
 				/* this label is marked up with <b> but shouldn't be */
-				label->set_markup ((*j)->name);
+				label->set_text ((*j)->name);
 			} else if (c.length() && c[0] != '<' && has_connection) {
 				/* this label is not marked up with <b> but should be */
-				label->set_markup (string_compose ("<b>%1</b>", (*j)->name));
+				label->set_markup (string_compose ("<b>%1</b>", Glib::Markup::escape_text ((*j)->name)));
 			}
 
 			++p;
diff --git a/gtk2_ardour/sfdb_ui.cc b/gtk2_ardour/sfdb_ui.cc
index d580418dac..eab34a6a0a 100644
--- a/gtk2_ardour/sfdb_ui.cc
+++ b/gtk2_ardour/sfdb_ui.cc
@@ -248,7 +248,7 @@ SoundFileBox::setup_labels (const string& filename)
 		return false;
 	}
 
-	preview_label.set_markup (string_compose ("<b>%1</b>", Glib::path_get_basename (filename)));
+	preview_label.set_markup (string_compose ("<b>%1</b>", Glib::Markup::escape_text (Glib::path_get_basename (filename))));
 	std::string n = sf_info.format_name;
 	if (n.substr (0, 8) == X_("Format: ")) {
 		n = n.substr (8);
diff --git a/gtk2_ardour/splash.cc b/gtk2_ardour/splash.cc
index ad7585e541..b2777eb48c 100644
--- a/gtk2_ardour/splash.cc
+++ b/gtk2_ardour/splash.cc
@@ -188,7 +188,7 @@ void
 Splash::message (const string& msg)
 {
 	string str ("<b>");
-	str += msg;
+	str += Glib::Markup::escape_text (msg);
 	str += "</b>";
 
 	layout->set_markup (str);