diff --git a/test/algorithms/test_union.hpp b/test/algorithms/test_union.hpp
index 70dd3783e..1f878ed02 100644
--- a/test/algorithms/test_union.hpp
+++ b/test/algorithms/test_union.hpp
@@ -50,7 +50,7 @@ void test_union(std::string const& caseid, G1 const& g1, G2 const& g2,
 
     bg::union_(g1, g2, clip);
 
-    typename bg::default_area_result<G1>::type area = 0;
+    typename bg::default_area_result<OutputType>::type area = 0;
     std::size_t n = 0;
     std::size_t holes = 0;
     for (typename std::vector<OutputType>::iterator it = clip.begin();
@@ -69,7 +69,7 @@ void test_union(std::string const& caseid, G1 const& g1, G2 const& g2,
         array_with_one_empty_geometry.push_back(OutputType());
         boost::copy(array_with_one_empty_geometry, bg::detail::union_::union_insert<OutputType>(g1, g2, std::back_inserter(inserted)));
 
-        typename bg::default_area_result<G1>::type area_inserted = 0;
+        typename bg::default_area_result<OutputType>::type area_inserted = 0;
         int index = 0;
         for (typename std::vector<OutputType>::iterator it = inserted.begin();
                 it != inserted.end();