diff --git a/include/mapnik/cairo_renderer.hpp b/include/mapnik/cairo_renderer.hpp
index 75363b9f8..094bbbdd5 100644
--- a/include/mapnik/cairo_renderer.hpp
+++ b/include/mapnik/cairo_renderer.hpp
@@ -51,7 +51,7 @@
 // apps using mapnik do not
 // need agg headers
 namespace agg {
-  class trans_affine;
+  struct trans_affine;
 }
 
 namespace mapnik {