diff --git a/src/algorithms/local_search/insertion_search.h b/src/algorithms/local_search/insertion_search.h
index acbf60bab..3c6422619 100644
--- a/src/algorithms/local_search/insertion_search.h
+++ b/src/algorithms/local_search/insertion_search.h
@@ -178,6 +178,7 @@ RouteInsertion compute_best_insertion_pd(const Input& input,
       }
     }
   }
+  assert(result.cost <= cost_threshold);
   if (result.cost == cost_threshold) {
     result.cost = std::numeric_limits<Gain>::max();
   }
diff --git a/src/problems/cvrp/operators/pd_shift.cpp b/src/problems/cvrp/operators/pd_shift.cpp
index f2b324379..2c8e2461e 100644
--- a/src/problems/cvrp/operators/pd_shift.cpp
+++ b/src/problems/cvrp/operators/pd_shift.cpp
@@ -31,6 +31,7 @@ PDShift::PDShift(const Input& input,
   assert(s_route.size() >= 2);
   assert(s_p_rank < s_d_rank);
   assert(s_d_rank < s_route.size());
+  assert(s_route.route[s_p_rank] + 1 == s_route.route[s_d_rank]);
 
   stored_gain = gain_threshold;
 }
diff --git a/src/problems/vrptw/operators/pd_shift.cpp b/src/problems/vrptw/operators/pd_shift.cpp
index e912deab2..e9e7d0457 100644
--- a/src/problems/vrptw/operators/pd_shift.cpp
+++ b/src/problems/vrptw/operators/pd_shift.cpp
@@ -33,7 +33,6 @@ PDShift::PDShift(const Input& input,
                   static_cast<RawRoute&>(tw_t_route),
                   t_vehicle,
                   gain_threshold),
-    _is_valid_removal(true),
     _source_without_pd(s_route.begin() + _s_p_rank + 1,
                        s_route.begin() + _s_d_rank),
     _tw_s_route(tw_s_route),
@@ -42,19 +41,13 @@ PDShift::PDShift(const Input& input,
 
 void PDShift::compute_gain() {
   // Check for valid removal wrt TW constraints.
-  if (_s_d_rank == _s_p_rank + 1) {
-    _is_valid_removal =
-      _is_valid_removal && _tw_s_route.is_valid_removal(_input, _s_p_rank, 2);
-  } else {
-    _is_valid_removal =
-      _is_valid_removal &&
-      _tw_s_route.is_valid_addition_for_tw(_input,
-                                           _source_without_pd.begin(),
-                                           _source_without_pd.end(),
-                                           _s_p_rank,
-                                           _s_d_rank + 1);
-  }
-  if (!_is_valid_removal) {
+  bool is_valid_removal =
+    _tw_s_route.is_valid_addition_for_tw(_input,
+                                         _source_without_pd.begin(),
+                                         _source_without_pd.end(),
+                                         _s_p_rank,
+                                         _s_d_rank + 1);
+  if (!is_valid_removal) {
     return;
   }
 
@@ -64,12 +57,10 @@ void PDShift::compute_gain() {
                                   t_vehicle,
                                   _tw_t_route,
                                   _remove_gain - stored_gain);
-  assert(s_route[_s_p_rank] + 1 == s_route[_s_d_rank]);
 
   if (rs.cost < std::numeric_limits<Gain>::max()) {
-    assert(_remove_gain + -rs.cost > stored_gain);
     _valid = true;
-    stored_gain = _remove_gain + -rs.cost;
+    stored_gain = _remove_gain - rs.cost;
     _best_t_p_rank = rs.pickup_rank;
     _best_t_d_rank = rs.delivery_rank;
   }
diff --git a/src/problems/vrptw/operators/pd_shift.h b/src/problems/vrptw/operators/pd_shift.h
index e929b07fe..f7827ad52 100644
--- a/src/problems/vrptw/operators/pd_shift.h
+++ b/src/problems/vrptw/operators/pd_shift.h
@@ -17,7 +17,6 @@ namespace vrptw {
 
 class PDShift : public cvrp::PDShift {
 private:
-  bool _is_valid_removal;
   std::vector<Index> _source_without_pd;
   TWRoute& _tw_s_route;
   TWRoute& _tw_t_route;