diff --git a/gtk2_ardour/audio_clock.cc b/gtk2_ardour/audio_clock.cc
index 777700e3e0..8a3df6d61c 100644
--- a/gtk2_ardour/audio_clock.cc
+++ b/gtk2_ardour/audio_clock.cc
@@ -816,7 +816,7 @@ AudioClock::session_configuration_changed (std::string p)
 
 	if (p == "sync-source" || p == "external-sync") {
 		if (is_duration) {
-			AudioClock::set_duration (current_duration(), true);
+			set_duration (current_duration(), true);
 		} else {
 			AudioClock::set (current_time(), true);
 		}
@@ -827,7 +827,7 @@ AudioClock::session_configuration_changed (std::string p)
 		switch (_mode) {
 		case Timecode:
 			if (is_duration) {
-				AudioClock::set_duration (current_duration(), true);
+				set_duration (current_duration(), true);
 			} else {
 				AudioClock::set (current_time(), true);
 			}
@@ -2355,7 +2355,7 @@ AudioClock::set_off (bool yn)
 	 */
 
 	if (is_duration) {
-		AudioClock::set_duration (last_time, true);
+		set_duration (last_time, true);
 	} else {
 		AudioClock::set (last_when(), true);
 	}
diff --git a/gtk2_ardour/main_clock.cc b/gtk2_ardour/main_clock.cc
index 747048b57b..e582116ca6 100644
--- a/gtk2_ardour/main_clock.cc
+++ b/gtk2_ardour/main_clock.cc
@@ -126,12 +126,12 @@ MainClock::set (timepos_t const & when, bool force)
 			AudioClock::set (when, force);
 			break;
 		case DeltaEditPoint:
-			AudioClock::set_duration (when.distance (PublicEditor::instance().get_preferred_edit_position (Editing::EDIT_IGNORE_PHEAD)), force);
+			set_duration (when.distance (PublicEditor::instance().get_preferred_edit_position (Editing::EDIT_IGNORE_PHEAD)), force);
 			break;
 		case DeltaOriginMarker:
 			{
 				Location* loc = AudioEngine::instance()->session()->locations()->clock_origin_location ();
-				AudioClock::set_duration (-when.distance (loc ? loc->start() : timepos_t (when.time_domain())), force);
+				set_duration (-when.distance (loc ? loc->start() : timepos_t (when.time_domain())), force);
 			}
 			break;
 	}