diff --git a/libs/ardour/ardour/location.h b/libs/ardour/ardour/location.h
index 7015047b77..e6f65fc389 100644
--- a/libs/ardour/ardour/location.h
+++ b/libs/ardour/ardour/location.h
@@ -55,6 +55,7 @@ class LIBARDOUR_API Location : public SessionHandleRef, public PBD::StatefulDest
 		IsSessionRange = 0x40,
 		IsSkip = 0x80,
 		IsSkipping = 0x100, /* skipping is active (or not) */
+		IsClockOrigin = 0x200,
 	};
 
 	Location (Session &);
@@ -87,6 +88,7 @@ class LIBARDOUR_API Location : public SessionHandleRef, public PBD::StatefulDest
 	void set_hidden (bool yn, void *src);
 	void set_cd (bool yn, void *src);
 	void set_is_range_marker (bool yn, void* src);
+	void set_is_clock_origin (bool yn, void* src);
 	void set_skip (bool yn);
 	void set_skipping (bool yn);
 
@@ -98,6 +100,7 @@ class LIBARDOUR_API Location : public SessionHandleRef, public PBD::StatefulDest
 	bool is_session_range () const { return _flags & IsSessionRange; }
 	bool is_range_marker() const { return _flags & IsRangeMarker; }
 	bool is_skip() const { return _flags & IsSkip; }
+	bool is_clock_origin() const { return _flags & IsClockOrigin; }
 	bool is_skipping() const { return (_flags & IsSkip) && (_flags & IsSkipping); }
 	bool matches (Flags f) const { return _flags & f; }
 
@@ -189,6 +192,7 @@ class LIBARDOUR_API Locations : public SessionHandleRef, public PBD::StatefulDes
 	Location* auto_loop_location () const;
 	Location* auto_punch_location () const;
 	Location* session_range_location() const;
+	Location* clock_origin_location() const;
 
 	int next_available_name(std::string& result,std::string base);
 	uint32_t num_range_markers() const;
@@ -198,6 +202,8 @@ class LIBARDOUR_API Locations : public SessionHandleRef, public PBD::StatefulDes
 
 	Location* mark_at (samplepos_t, samplecnt_t slop = 0) const;
 
+	void set_clock_origin (Location*, void *src);
+
 	samplepos_t first_mark_before (samplepos_t, bool include_special_ranges = false);
 	samplepos_t first_mark_after (samplepos_t, bool include_special_ranges = false);
 
diff --git a/libs/ardour/enums.cc b/libs/ardour/enums.cc
index 09ae6db6b7..7899f8f15f 100644
--- a/libs/ardour/enums.cc
+++ b/libs/ardour/enums.cc
@@ -530,6 +530,7 @@ setup_enum_writer ()
 	REGISTER_CLASS_ENUM (Location, IsSessionRange);
 	REGISTER_CLASS_ENUM (Location, IsRangeMarker);
 	REGISTER_CLASS_ENUM (Location, IsSkip);
+	REGISTER_CLASS_ENUM (Location, IsClockOrigin);
 	REGISTER_BITS (_Location_Flags);
 
 	REGISTER_CLASS_ENUM (TempoSection, Ramp);
diff --git a/libs/ardour/location.cc b/libs/ardour/location.cc
index 04e36589ee..24774c5fec 100644
--- a/libs/ardour/location.cc
+++ b/libs/ardour/location.cc
@@ -478,6 +478,15 @@ Location::set_is_range_marker (bool yn, void*)
 	}
 }
 
+void
+Location::set_is_clock_origin (bool yn, void*)
+{
+	if (set_flag_internal (yn, IsClockOrigin)) {
+		flags_changed (this);
+		FlagsChanged (); /* EMIT SIGNAL */
+	}
+}
+
 void
 Location::set_skip (bool yn)
 {
@@ -800,6 +809,20 @@ Locations::set_current (Location *loc, bool want_lock)
 	return ret;
 }
 
+void
+Locations::set_clock_origin (Location* loc, void *src)
+{
+	LocationList::iterator i;
+	for (i = locations.begin(); i != locations.end(); ++i) {
+		if ((*i)->is_clock_origin ()) {
+			(*i)->set_is_clock_origin (false, src);
+		}
+		if (*i == loc) {
+			(*i)->set_is_clock_origin (true, src);
+		}
+	}
+}
+
 int
 Locations::next_available_name(string& result,string base)
 {
@@ -1401,6 +1424,17 @@ Locations::auto_punch_location () const
 	return 0;
 }
 
+Location*
+Locations::clock_origin_location () const
+{
+	for (LocationList::const_iterator i = locations.begin(); i != locations.end(); ++i) {
+		if ((*i)->is_clock_origin()) {
+			return const_cast<Location*> (*i);
+		}
+	}
+	return session_range_location ();
+}
+
 uint32_t
 Locations::num_range_markers () const
 {