diff --git a/test/algorithms/set_operations/intersection/intersection.cpp b/test/algorithms/set_operations/intersection/intersection.cpp
index 4bcbf29d4..834456bea 100644
--- a/test/algorithms/set_operations/intersection/intersection.cpp
+++ b/test/algorithms/set_operations/intersection/intersection.cpp
@@ -46,9 +46,13 @@ BOOST_GEOMETRY_REGISTER_LINESTRING_TEMPLATED(std::vector)
     (test_one<Polygon, Polygon, Polygon>) \
     ( #caseid, caseid[0], caseid[1], clips, points, area)
 
-#define TEST_INTERSECTION_IGNORE(caseid, clips, points, area) \
-    (test_one<Polygon, Polygon, Polygon>) \
-    ( #caseid, caseid[0], caseid[1], clips, points, area, ignore_validity)
+#if ! defined(BOOST_GEOMETRY_INCLUDE_SELF_TURNS)
+    #define TEST_INTERSECTION_IGNORE(caseid, clips, points, area) \
+        { ut_settings ignore_validity; \
+        ignore_validity.test_validity = false; \
+        (test_one<Polygon, Polygon, Polygon>) \
+        ( #caseid, caseid[0], caseid[1], clips, points, area, ignore_validity); }
+#endif
 
 template <typename Polygon>
 void test_areal()
@@ -57,10 +61,6 @@ void test_areal()
     bool const ccw = bg::point_order<Polygon>::value == bg::counterclockwise;
     bool const open = bg::closure<Polygon>::value == bg::open;
 
-    ut_settings ignore_validity;
-    ignore_validity.test_validity = false;
-
-
     test_one<Polygon, Polygon, Polygon>("simplex_with_empty_1",
         simplex_normal[0], polygon_empty,
         0, 0, 0.0);
@@ -174,20 +174,21 @@ void test_areal()
         pie_2_3_23_0[0], pie_2_3_23_0[1],
         1, 4, 163292.679042133, ut_settings(0.1));
 
+    {
+        ut_settings settings(if_typed_tt<ct>(0.01, 0.1));
+
 #if defined(BOOST_GEOMETRY_NO_ROBUSTNESS)
-    test_one<Polygon, Polygon, Polygon>("isovist",
-        isovist1[0], isovist1[1],
-        1, 19, 88.4178,
-        ignore_validity);
-#else
-    // SQL Server gives: 88.1920416352664
-    // PostGIS gives:    88.19203677911
-    test_one<Polygon, Polygon, Polygon>("isovist",
-        isovist1[0], isovist1[1],
-        1, 19, 88.19203,
-        ut_settings(if_typed_tt<ct>(0.01, 0.1)));
+        settings.test_validity = false;
 #endif
 
+        // SQL Server gives: 88.1920416352664
+        // PostGIS gives:    88.19203677911
+        test_one<Polygon, Polygon, Polygon>("isovist",
+            isovist1[0], isovist1[1],
+            1, 19, 88.192037,
+            settings);
+    }
+
     test_one<Polygon, Polygon, Polygon>("geos_1",
         geos_1[0], geos_1[1],
             1, -1, 3461.0214843, // MSVC 14 reports 3461.025390625
@@ -346,8 +347,13 @@ void test_areal()
         case_102[0], case_102[1],
         0, -1, 3.1875);
 
+#ifdef BOOST_GEOMETRY_INCLUDE_SELF_TURNS
+    TEST_INTERSECTION(case_103, 2, -1, 3.5);
+    TEST_INTERSECTION(case_104, 3, -1, 3.0);
+#else
     TEST_INTERSECTION_IGNORE(case_103, 0, -1, 3.5);
     TEST_INTERSECTION_IGNORE(case_104, 0, -1, 3.0);
+#endif
 
     test_one<Polygon, Polygon, Polygon>("mysql_21964049",
         mysql_21964049[0], mysql_21964049[1],