diff --git a/CHANGELOG b/CHANGELOG
index eebfb533f..e85018ea2 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -11,7 +11,14 @@ Developers: Please commit along with changes.
 For a complete change history, see the SVN log.
 
 
-Mapnik Trunk
+Mapnik 2.1.0
+------------
+
+- Fixed bug in shield line placement when dx/dy are used to shift the label relative to the placement point (Matt Amos) (#908)
+
+
+
+Mapnik 2.0.0
 ------------
 
 - Add minimum-path-length property to text_symbolizer to allow labels to be placed only on lines of a certain length (#865)
diff --git a/include/mapnik/placement_finder.hpp b/include/mapnik/placement_finder.hpp
index a2368ed93..2a605d15b 100644
--- a/include/mapnik/placement_finder.hpp
+++ b/include/mapnik/placement_finder.hpp
@@ -77,6 +77,10 @@ struct placement : boost::noncopyable
     std::pair<double, double> dimensions;
     bool collect_extents;
     box2d<double> extents;
+
+    // additional boxes attached to the text labels which must also be
+    // placed in order for the text placement to succeed. e.g: shields.
+    std::vector<box2d<double> > additional_boxes;
 };
 
 
diff --git a/src/agg/process_shield_symbolizer.cpp b/src/agg/process_shield_symbolizer.cpp
index cb3591abc..2008939f0 100644
--- a/src/agg/process_shield_symbolizer.cpp
+++ b/src/agg/process_shield_symbolizer.cpp
@@ -229,12 +229,17 @@ void  agg_renderer<T>::process(shield_symbolizer const& sym,
 
                     else if (geom.num_points() > 1 && how_placed == LINE_PLACEMENT)
                     {
-                        placement text_placement(info, sym, scale_factor_, label_ext.width(), label_ext.height(), true);
-                        
+                        placement text_placement(info, sym, scale_factor_, w, h, false);
+                        position const& pos = sym.get_displacement();
+
                         text_placement.avoid_edges = sym.get_avoid_edges();
+                        text_placement.additional_boxes.push_back(
+                           box2d<double>(-0.5 * label_ext.width() - boost::get<0>(pos),
+                                         -0.5 * label_ext.height() - boost::get<1>(pos),
+                                         0.5 * label_ext.width() - boost::get<0>(pos),
+                                         0.5 * label_ext.height() - boost::get<1>(pos)));
                         finder.find_point_placements<path_type>(text_placement, placement_options, path);
 
-                        position const&  pos = sym.get_displacement();
                         for (unsigned int ii = 0; ii < text_placement.placements.size(); ++ ii)
                         {
                             double x = floor(text_placement.placements[ii].starting_x);
@@ -244,13 +249,13 @@ void  agg_renderer<T>::process(shield_symbolizer const& sym,
                             double ly = y - boost::get<1>(pos);
                             int px=int(floor(lx - (0.5*w))) + 1;
                             int py=int(floor(ly - (0.5*h))) + 1;
+                            label_ext.re_center(lx, ly);
 
                             render_marker(px,py,**marker,tr,sym.get_opacity());
 
-                            if (writer.first) writer.first->add_box(label_ext, feature, t_, writer.second);
-
                             box2d<double> dim = ren.prepare_glyphs(&text_placement.placements[ii]);
                             ren.render(x,y);
+                            if (writer.first) writer.first->add_box(label_ext, feature, t_, writer.second);
                         }
                         finder.update_detector(text_placement);
                         if (writer.first) writer.first->add_text(text_placement, faces, feature, t_, writer.second);
diff --git a/src/placement_finder.cpp b/src/placement_finder.cpp
index a57da1222..9813dab04 100644
--- a/src/placement_finder.cpp
+++ b/src/placement_finder.cpp
@@ -38,6 +38,7 @@
 #include <boost/utility.hpp>
 #include <boost/ptr_container/ptr_vector.hpp>
 #include <boost/tuple/tuple.hpp>
+#include <boost/foreach.hpp>
 
 //stl
 #include <string>
@@ -482,6 +483,23 @@ void placement_finder<DetectorT>::find_point_placement(placement & p,
         x += cwidth;  // move position to next character
     }
 
+    // check the placement of any additional envelopes
+    if (!p.allow_overlap && !p.additional_boxes.empty())
+    {
+       BOOST_FOREACH(box2d<double> box, p.additional_boxes) 
+       {
+          box2d<double> pt(box.minx() + current_placement->starting_x,
+                           box.miny() + current_placement->starting_y,
+                           box.maxx() + current_placement->starting_x,
+                           box.maxy() + current_placement->starting_y);
+
+          // abort the whole placement if the additional envelopes can't be placed.
+          if (!detector_.has_point_placement(pt, p.minimum_distance)) return;
+
+          c_envelopes.push(pt);
+       }
+    }
+
     // since there was no early exit, add the character envelopes to the placements' envelopes
     while( !c_envelopes.empty() )
     {