diff --git a/include/mapnik/cairo_renderer.hpp b/include/mapnik/cairo_renderer.hpp
index fbeb0f572..e95233c80 100644
--- a/include/mapnik/cairo_renderer.hpp
+++ b/include/mapnik/cairo_renderer.hpp
@@ -147,7 +147,6 @@ protected:
     std::shared_ptr<freetype_engine> font_engine_;
     face_manager<freetype_engine> font_manager_;
     cairo_face_manager face_manager_;
-    box2d<double> clip_extent_;
     std::shared_ptr<label_collision_detector4> detector_;
     box2d<double> query_extent_;
     void setup(Map const& m);
diff --git a/src/cairo_renderer.cpp b/src/cairo_renderer.cpp
index 14b9612d7..74c0b07bc 100644
--- a/src/cairo_renderer.cpp
+++ b/src/cairo_renderer.cpp
@@ -133,9 +133,9 @@ cairo_renderer_base::cairo_renderer_base(Map const& m,
       font_engine_(std::make_shared<freetype_engine>()),
       font_manager_(*font_engine_),
       face_manager_(font_engine_),
-      clip_extent_(-m.buffer_size(), -m.buffer_size(),
-                   m.width() + m.buffer_size(), m.height() + m.buffer_size()),
-      detector_(std::make_shared<label_collision_detector4>(clip_extent_))
+      detector_(std::make_shared<label_collision_detector4>(
+                  box2d<double>(-m.buffer_size(), -m.buffer_size(),
+                                m.width() + m.buffer_size(), m.height() + m.buffer_size())))
 {
     setup(m);
 }
@@ -155,9 +155,9 @@ cairo_renderer_base::cairo_renderer_base(Map const& m,
       font_engine_(std::make_shared<freetype_engine>()),
       font_manager_(*font_engine_),
       face_manager_(font_engine_),
-      clip_extent_(-m.buffer_size(), -m.buffer_size(),
-                   m.width() + m.buffer_size(), m.height() + m.buffer_size()),
-      detector_(std::make_shared<label_collision_detector4>(clip_extent_))
+      detector_(std::make_shared<label_collision_detector4>(
+                  box2d<double>(-m.buffer_size(), -m.buffer_size(),
+                                m.width() + m.buffer_size(), m.height() + m.buffer_size())))
 {
     setup(m);
 }
@@ -177,8 +177,6 @@ cairo_renderer_base::cairo_renderer_base(Map const& m,
       font_engine_(std::make_shared<freetype_engine>()),
       font_manager_(*font_engine_),
       face_manager_(font_engine_),
-      clip_extent_(-m.buffer_size(), -m.buffer_size(),
-                   m.width() + m.buffer_size(), m.height() + m.buffer_size()),
       detector_(detector)
 {
     MAPNIK_LOG_DEBUG(cairo_renderer) << "cairo_renderer_base: Scale=" << m.scale();