diff --git a/libs/surfaces/push2/buttons.cc b/libs/surfaces/push2/buttons.cc
index 44cdcac93e..9db1808cd8 100644
--- a/libs/surfaces/push2/buttons.cc
+++ b/libs/surfaces/push2/buttons.cc
@@ -38,10 +38,12 @@ Push2::build_maps ()
 
 	boost::shared_ptr<Pad> pad;
 
+	_xy_pad_map.assign (64, boost::shared_ptr<Pad>());
+
 #define MAKE_PAD(x,y,nn) \
 	pad.reset (new Pad ((x), (y), (nn))); \
 	_nn_pad_map.insert (std::make_pair (pad->extra(), pad)); \
-	_xy_pad_map.insert (std::make_pair (y * 8 + x, pad));
+	_xy_pad_map[y * 8 + x] = pad;
 
 	MAKE_PAD (0, 0, 92);
 	MAKE_PAD (0, 1, 93);
diff --git a/libs/surfaces/push2/push2.cc b/libs/surfaces/push2/push2.cc
index 68237f8982..1f9de05c77 100644
--- a/libs/surfaces/push2/push2.cc
+++ b/libs/surfaces/push2/push2.cc
@@ -1906,7 +1906,9 @@ Push2::set_pressure_mode (PressureMode pm)
 boost::shared_ptr<Push2::Pad>
 Push2::pad_by_xy (int x, int y)
 {
-	Push2::PadMap::iterator p = _xy_pad_map.find ((x * 8) +y);
-	assert (p != _xy_pad_map.end());
-	return p->second;
+	vector<boost::shared_ptr<Pad> >::size_type index = (x * 8) + y;
+	if (index >= _xy_pad_map.size()) {
+		return boost::shared_ptr<Pad>();
+	}
+	return _xy_pad_map[index];
 }
diff --git a/libs/surfaces/push2/push2.h b/libs/surfaces/push2/push2.h
index 89c7f005ca..f2467e909d 100644
--- a/libs/surfaces/push2/push2.h
+++ b/libs/surfaces/push2/push2.h
@@ -455,7 +455,6 @@ class Push2 : public ARDOUR::ControlProtocol
 
 	typedef std::map<int,boost::shared_ptr<Pad> > PadMap;
 	PadMap const & nn_pad_map() const { return _nn_pad_map; }
-	PadMap const & xy_pad_map() const { return _xy_pad_map; }
 
 	boost::shared_ptr<Pad> pad_by_xy (int x, int y);
 
@@ -499,9 +498,9 @@ class Push2 : public ARDOUR::ControlProtocol
 	 */
 	PadMap _nn_pad_map;
 
-	/* map of Pads by x,y duple (computed as (x*8) + y */
+	/* array of Pads by x,y duple (indexed as (x*8) + y */
 
-	PadMap _xy_pad_map;
+	std::vector<boost::shared_ptr<Pad> > _xy_pad_map;
 
 	/* map of Pads by note number they generate (their "filtered" value)
 	 */