diff --git a/include/mapnik/image_filter.hpp b/include/mapnik/image_filter.hpp
index 3d10326e3..b7ed8a3c6 100644
--- a/include/mapnik/image_filter.hpp
+++ b/include/mapnik/image_filter.hpp
@@ -142,6 +142,26 @@ boost::gil::rgba8_view_t rgba8_view(Image & img)
                             img.width() * sizeof(rgba8_pixel_t));
 }
 
+namespace detail {
+
+template <typename T>
+inline void premultiply_alpha( T & dst)
+{
+    auto alpha = dst[3];
+    if (alpha < 255)
+    {
+        if (alpha == 0)
+        {
+            dst[0] = dst[1] = dst[2] = 0;
+        }
+        dst[0] = (dst[0] * alpha + 255) >> 8;
+        dst[1] = (dst[1] * alpha + 255) >> 8;
+        dst[2] = (dst[2] * alpha + 255) >> 8;
+    }
+}
+
+}
+
 template <typename Image>
 struct double_buffer
 {
@@ -284,13 +304,13 @@ void apply_convolution_3x3(Src const& src_view, Dst & dst_view, Filter const& fi
                 p[8] = src_loc[loc22][i];
             }
 
-
             p[0] = p[6];
             p[1] = p[7];
             p[2] = p[8];
 
             process_channel(p, (*dst_it)[i], filter);
         }
+        detail::premultiply_alpha(*dst_it);
         ++src_loc.x();
         ++dst_it;
     }
@@ -338,6 +358,8 @@ void apply_convolution_3x3(Src const& src_view, Dst & dst_view, Filter const& fi
                 }
                 process_channel(p, (*dst_it)[i], filter);
             }
+
+            detail::premultiply_alpha(*dst_it);
             ++dst_it;
             ++src_loc.x();
         }
@@ -383,9 +405,9 @@ void apply_convolution_3x3(Src const& src_view, Dst & dst_view, Filter const& fi
             p[6] = p[0];
             p[7] = p[1];
             p[8] = p[2];
-
             process_channel(p, (*dst_it)[i], filter);
         }
+        detail::premultiply_alpha(*dst_it);
         ++src_loc.x();
         ++dst_it;
     }