diff --git a/deps/agg/include/agg_vpgen_clip_polyline.h b/deps/agg/include/agg_vpgen_clip_polyline.h
index b070a7759..a2e60fa7b 100644
--- a/deps/agg/include/agg_vpgen_clip_polyline.h
+++ b/deps/agg/include/agg_vpgen_clip_polyline.h
@@ -18,6 +18,9 @@
 
 #include "agg_basics.h"
 
+// https://github.com/mapnik/mapnik/issues/1860
+#include <mapnik/config.hpp>
+
 namespace agg
 {
 
@@ -25,7 +28,7 @@ namespace agg
     //
     // See Implementation agg_vpgen_clip_polyline.cpp
     //
-    class vpgen_clip_polyline
+    class MAPNIK_DECL vpgen_clip_polyline
     {
     public:
         vpgen_clip_polyline() :