diff --git a/include/mapnik/hextree.hpp b/include/mapnik/hextree.hpp
index 3ac09cc04..f3350b3fc 100644
--- a/include/mapnik/hextree.hpp
+++ b/include/mapnik/hextree.hpp
@@ -434,7 +434,7 @@ private:
             }
             tries=0;
             // ignore leaves and also nodes with small mean error and not excessive number of pixels
-            if ((cur_node->reduce_cost / cur_node->pixel_count + 1) * std::log(long(cur_node->pixel_count)) > 15
+            if (cur_node->pixel_count > 0 && (cur_node->reduce_cost / cur_node->pixel_count + 1) * std::log(long(cur_node->pixel_count)) > 15
                 && cur_node->children_count > 0)
             {
                 colors_--;
diff --git a/src/palette.cpp b/src/palette.cpp
index 8ef8018fc..87c5c5055 100644
--- a/src/palette.cpp
+++ b/src/palette.cpp
@@ -35,10 +35,11 @@ bool rgba::mean_sort_cmp::operator() (const rgba& x, const rgba& y) const
     int t2 = (int)y.a + y.r + y.g + y.b;
     if (t1 != t2) return t1 < t2;
 
-    return (((int)x.a - y.a) >> 24) +
-           (((int)x.r - y.r) >> 16) +
-           (((int)x.g - y.g) >> 8) +
-           (((int)x.b - y.b));
+    // https://github.com/mapnik/mapnik/issues/1087
+    if (x.a != y.a) return x.a < y.a;
+    if (x.r != y.r) return x.r < y.r;
+    if (x.g != y.g) return x.g < y.g;
+    return x.b < y.b;
 }
 
 std::size_t rgba::hash_func::operator()(rgba const& p) const