diff --git a/include/boost/geometry/algorithms/detail/overlay/assign_parents.hpp b/include/boost/geometry/algorithms/detail/overlay/assign_parents.hpp
index 7b00e6496c..2c68d3087e 100644
--- a/include/boost/geometry/algorithms/detail/overlay/assign_parents.hpp
+++ b/include/boost/geometry/algorithms/detail/overlay/assign_parents.hpp
@@ -249,7 +249,6 @@ inline void assign_parents(Geometry1 const& geometry1,
             RingMap& ring_map,
             Strategy const& strategy)
 {
-    static bool const is_difference = OverlayType == overlay_difference;
     static bool const is_buffer = OverlayType == overlay_buffer;
     static bool const is_dissolve = OverlayType == overlay_dissolve;
     static bool const check_for_orientation = is_buffer || is_dissolve;
@@ -316,7 +315,7 @@ inline void assign_parents(Geometry1 const& geometry1,
                 return;
             }
 
-            if (count_positive == 1 && ! is_difference && ! is_dissolve)
+            if (count_positive == 1 && OverlayType == overlay_union)
             {
                 // Optimization for one outer ring
                 // -> assign this as parent to all others (all interior rings)
diff --git a/test/algorithms/set_operations/set_ops_areal_areal.cpp b/test/algorithms/set_operations/set_ops_areal_areal.cpp
index 1506f5fceb..2f819673ff 100644
--- a/test/algorithms/set_operations/set_ops_areal_areal.cpp
+++ b/test/algorithms/set_operations/set_ops_areal_areal.cpp
@@ -298,10 +298,7 @@ int test_main(int, char* [])
 
     TEST_CASE(case_bitset_1);
     TEST_CASE(case_bitset_2);
-#if defined(BOOST_GEOMETRY_TEST_FAILURES)
-    // Needs a fix in assign_parents
     TEST_CASE(case_bitset_3);
-#endif
 
     TEST_CASE(case_recursive_boxes_89);
     TEST_CASE(case_recursive_boxes_90);