diff --git a/libs/canvas/constraint_test3.cc b/libs/canvas/constraint_test3.cc
new file mode 100644
index 0000000000..0ddb7ff7c7
--- /dev/null
+++ b/libs/canvas/constraint_test3.cc
@@ -0,0 +1,96 @@
+#include <iostream>
+
+#include <gtkmm/adjustment.h>
+#include <gtkmm/main.h>
+#include <gtkmm/window.h>
+
+#include "gtkmm2ext/colors.h"
+
+#include "canvas/box.h"
+#include "canvas/canvas.h"
+#include "canvas/cbox.h"
+#include "canvas/circle.h"
+#include "canvas/constrained_item.h"
+#include "canvas/constraint_packer.h"
+#include "canvas/rectangle.h"
+#include "canvas/text.h"
+
+using namespace ArdourCanvas;
+using namespace Gtk;
+using std::cerr;
+using std::endl;
+
+int
+main (int argc, char* argv[])
+{
+	Gtk::Main app (&argc, &argv);
+
+	Gtk::Window win;
+	Gtk::Adjustment hadj (0, 0, 1000, 1, 10);
+	Gtk::Adjustment vadj (0, 0, 1000, 1, 10);
+	GtkCanvasViewport cview (hadj, vadj);
+	Canvas* c = cview.canvas ();
+
+	c->set_background_color (0xffffffff);
+
+	srandom (time ((time_t) 0));
+
+	cview.set_size_request (100, 100);
+
+	win.add (cview);
+
+	Rectangle* r1 = new Rectangle (c);
+	Rectangle* r2 = new Rectangle (c);
+	Rectangle* r3 = new Rectangle (c);
+
+	r1->set_fill_color (Gtkmm2ext::random_color());
+	r2->set_fill_color (Gtkmm2ext::random_color());
+	r3->set_fill_color (Gtkmm2ext::random_color());
+
+	r1->name = "r1";
+	r2->name = "r2";
+	r3->name = "r3";
+
+	r1->set_intrinsic_size (20, 20);
+	r2->set_intrinsic_size (30, 30);
+	r3->set_intrinsic_size (40, 40);
+
+	ConstraintPacker* packer = new ConstraintPacker (c->root());
+
+	ConstrainedItem* left = packer->add_constrained (r1);
+	ConstrainedItem* right = packer->add_constrained (r2);
+	ConstrainedItem* center = packer->add_constrained (r3);
+
+	/* x-axis */
+
+	packer->constrain (left->left() == 0);
+	packer->constrain (center->left() == left->right());
+	packer->constrain (right->left() == center->right());
+
+	packer->constrain (left->width() == packer->width * 0.4);
+	packer->constrain (center->width() == packer->width * 0.1);
+	packer->constrain (left->width() + right->width() + center->width() == packer->width);
+
+	packer->constrain (left->right() == left->left() + left->width());
+	packer->constrain (right->right() == right->left() + right->width());
+	packer->constrain (center->right() == center->left() + center->width());
+
+	/* y-axis */
+
+	packer->constrain (left->top() == 0);
+	packer->constrain (right->top() == left->top());
+	packer->constrain (center->top() == left->top());
+
+	packer->constrain (left->height() == packer->height);
+	packer->constrain (right->height() == left->height());
+	packer->constrain (center->height() == left->height());
+
+	packer->constrain (left->bottom() == left->top() + left->height());
+	packer->constrain (center->bottom() == center->top() + center->height());
+	packer->constrain (right->bottom() == right->top() + right->height());
+
+	win.show_all ();
+	app.run ();
+
+	return 0;
+}
diff --git a/libs/canvas/wscript b/libs/canvas/wscript
index 06b3755e06..10e93772d9 100644
--- a/libs/canvas/wscript
+++ b/libs/canvas/wscript
@@ -181,6 +181,15 @@ def build(bld):
     constraint_test2.name         = 'constraint_test2'
     constraint_test2.target       = 'constraint_test2'
     constraint_test2.install_path = ''
+
+    constraint_test3_src = [ 'constraint_test3.cc' ]
+    constraint_test3 = bld (features = 'cxx cxxprogram')
+    constraint_test3.source = constraint_test3_src
+    constraint_test3.includes = obj.includes + ['../pbd', '../gtkmm2ext']
+    constraint_test3.use = [ 'GTKMM', 'libcanvas', 'libgtkmm2ext' ]
+    constraint_test3.name         = 'constraint_test3'
+    constraint_test3.target       = 'constraint_test3'
+    constraint_test3.install_path = ''
     
 def shutdown():
     autowaf.shutdown()