diff --git a/include/boost/geometry/algorithms/detail/overlay/handle_colocations.hpp b/include/boost/geometry/algorithms/detail/overlay/handle_colocations.hpp
index 4b84f2ae4..275bb8eed 100644
--- a/include/boost/geometry/algorithms/detail/overlay/handle_colocations.hpp
+++ b/include/boost/geometry/algorithms/detail/overlay/handle_colocations.hpp
@@ -199,77 +199,6 @@ inline signed_size_type add_turn_to_cluster(Turn const& turn,
     return cid0;
 }
 
-/// Discards turn colocated with a uu turn, where both turns are on the same
-/// rings and one is (most probably) invalid
-template
-<
-    bool Reverse1, bool Reverse2,
-    typename Turns,
-    typename Geometry1,
-    typename Geometry2
->
-inline bool discard_colocated_uu(signed_size_type cluster_id,
-        Turns const& turns,
-        turn_operation_index const& ref_toi,
-        turn_operation_index const& toi,
-        Geometry1 const& geometry1, Geometry2 const& geometry2)
-{
-    typedef typename boost::range_value<Turns>::type turn_type;
-    typedef typename geometry::point_type<Geometry1>::type point_type;
-
-    // Order counter clockwise to get the most right turn
-    typedef sort_by_side::side_sorter
-        <
-            Reverse1, Reverse2, point_type, std::less<int>
-        > sbs_type;
-
-    sbs_type sbs;
-
-    turn_type const& ref_turn = turns[ref_toi.turn_index];
-    turn_type const& turn = turns[toi.turn_index];
-
-    // Add operations, the first is the "subject" (so sorting done from there)
-    BOOST_ASSERT(ref_turn.both(operation_union));
-    sbs.add(ref_turn.operations[ref_toi.op_index],
-            ref_toi.turn_index, ref_toi.op_index,
-            geometry1, geometry2, true);
-    sbs.add(ref_turn.operations[1 - ref_toi.op_index],
-            ref_toi.turn_index, 1 - ref_toi.op_index,
-            geometry1, geometry2, false);
-
-    // Skip toi.op_index because ref_toi and toi have the same operation
-    BOOST_ASSERT(ref_turn.operations[ref_toi.op_index].seg_id
-            == turn.operations[toi.op_index].seg_id);
-
-    sbs.add(turn.operations[1 - toi.op_index],
-            toi.turn_index, 1 - toi.op_index,
-            geometry1, geometry2, false);
-
-    sbs.apply(ref_turn.point);
-
-    // Inspect points, the first right turn has main_rank==1
-    // If this is still from the same source, with no others in between, it
-    // should be discarded
-    signed_size_type const source_index
-            = ref_turn.operations[ref_toi.op_index].seg_id.source_index;
-    for (std::size_t i = 0; i < sbs.m_ranked_points.size(); i++)
-    {
-        const typename sbs_type::rp& ranked_point = sbs.m_ranked_points[i];
-        if (ranked_point.main_rank > 1)
-        {
-            break;
-        }
-        if (ranked_point.seg_id.source_index != source_index)
-        {
-            // Other sources in between or collinear with it, don't discard
-            return false;
-        }
-    }
-
-    // Discard this turn
-    return true;
-}
-
 template
 <
     bool Reverse1, bool Reverse2,
@@ -308,8 +237,6 @@ inline void handle_colocation_cluster(Turns& turns,
 
         if (ref_op.fraction == op.fraction)
         {
-            turn_operation_type const& ref_other_op
-                    = ref_turn.operations[1 - ref_toi.op_index];
             turn_operation_type const& other_op = turn.operations[1 - toi.op_index];
 
             if (ref_id == -1)
@@ -340,19 +267,6 @@ inline void handle_colocation_cluster(Turns& turns,
                 turn.discarded = true;
                 // We can either set or not set colocated because it is not effective on blocked turns
             }
-
-            if (ref_turn.both(operation_union)
-                && ! turn.both(operation_union))
-            {
-                if (other_op.seg_id.multi_index == ref_other_op.seg_id.multi_index
-                    && other_op.seg_id.ring_index == ref_other_op.seg_id.ring_index
-                    && discard_colocated_uu<Reverse1, Reverse2>(id,
-                        turns, ref_toi, toi, geometry1, geometry2))
-                {
-                    turn.discarded = true;
-                    turn.colocated = true;
-                }
-            }
         }
         else
         {
diff --git a/test/algorithms/overlay/multi_overlay_cases.hpp b/test/algorithms/overlay/multi_overlay_cases.hpp
index 07dc91370..7be83fc6c 100644
--- a/test/algorithms/overlay/multi_overlay_cases.hpp
+++ b/test/algorithms/overlay/multi_overlay_cases.hpp
@@ -601,10 +601,18 @@ static std::string case_recursive_boxes_28[2] =
 
 static std::string case_recursive_boxes_29[2] =
 {
+    // Requires not discarding colocated cc turns
     "MULTIPOLYGON(((2 3,2 4,1 4,2 5,4 5,4 4,3 4,3 3,2 3)),((3 3,4 3,4 1,5 1,5 0,3 0,3 2,2 2,3 3)),((1 2,0 2,0 3,1 3,1 2)),((1 1,0 1,1 2,2 2,2 1,1 1)),((2 1,2 0,1 0,2 1)))",
     "MULTIPOLYGON(((0 4,0 5,1 4,0 4)),((2 3,2 4,4 4,4 3,2 3)),((2 2,1 2,1 3,2 3,2 2)),((1 2,0 2,0 3,1 3,0.5 2.5,1 2)),((1 0,0 0,1 1,4 1,4 0,1 0)),((4 0,5 1,5 0,4 0)))"
 };
 
+static std::string case_recursive_boxes_30[2] =
+{
+    // Requires not discarding turns colocated with uu/invalid polygons (now not necessary anymore because of startable)
+    "MULTIPOLYGON(((2 2,2 3,4 3,4 4,4.5 3.5,5 4,5 0,3 0,3 1,4 1,4 2,2 2)),((1 5,3 5,4 4,0 4,0 5,1 5)))",
+    "MULTIPOLYGON(((2 1,2 3,1 3,1 4,2 5,2 4,3 4,3 5,5 5,5 4,4 4,3.5 3.5,4 3,4 4,5 3,4.5 2.5,5 2,5 0,4 0,4 2,3 2,3 3,2.5 2.5,4 1,3 1,3 0,1 0,2 1)))"
+};
+
 static std::string pie_21_7_21_0_3[2] =
 {
     "MULTIPOLYGON(((2500 2500,2500 3875,2855 3828,3187 3690,3472 3472,3690 3187,3828 2855,3875 2500,3828 2144,3690 1812,3472 1527,3187 1309,2855 1171,2499 1125,2144 1171,1812 1309,1527 1527,1309 1812,1171 2144,1125 2499,1171 2855,1309 3187,2500 2500)))",
diff --git a/test/algorithms/set_operations/intersection/intersection_multi.cpp b/test/algorithms/set_operations/intersection/intersection_multi.cpp
index 58133c558..511dc4bca 100644
--- a/test/algorithms/set_operations/intersection/intersection_multi.cpp
+++ b/test/algorithms/set_operations/intersection/intersection_multi.cpp
@@ -213,6 +213,9 @@ void test_areal()
     test_one<Polygon, MultiPolygon, MultiPolygon>("case_recursive_boxes_29",
         case_recursive_boxes_29[0], case_recursive_boxes_29[1],
         5, 0, 3.75);
+    test_one<Polygon, MultiPolygon, MultiPolygon>("case_recursive_boxes_30",
+        case_recursive_boxes_30[0], case_recursive_boxes_30[1],
+        4, 0, 6.0);
 
     test_one<Polygon, MultiPolygon, MultiPolygon>("ggl_list_20120915_h2_a",
         ggl_list_20120915_h2[0], ggl_list_20120915_h2[1],
diff --git a/test/algorithms/set_operations/union/union_multi.cpp b/test/algorithms/set_operations/union/union_multi.cpp
index 4e233b57a..b6a20102f 100644
--- a/test/algorithms/set_operations/union/union_multi.cpp
+++ b/test/algorithms/set_operations/union/union_multi.cpp
@@ -204,6 +204,9 @@ void test_areal()
     test_one<Polygon, MultiPolygon, MultiPolygon>("case_recursive_boxes_29",
         case_recursive_boxes_29[0], case_recursive_boxes_29[1],
             2, 0, -1, 15.5);
+    test_one<Polygon, MultiPolygon, MultiPolygon>("case_recursive_boxes_30",
+        case_recursive_boxes_30[0], case_recursive_boxes_30[1],
+            1, 1, -1, 17.5);
 
     test_one<Polygon, MultiPolygon, MultiPolygon>("ggl_list_20120915_h2_a",
          ggl_list_20120915_h2[0], ggl_list_20120915_h2[1],