diff --git a/src/core/pal/labelposition.cpp b/src/core/pal/labelposition.cpp
index 68ec0eeffb0..6bc7bbfc7e9 100644
--- a/src/core/pal/labelposition.cpp
+++ b/src/core/pal/labelposition.cpp
@@ -476,7 +476,7 @@ bool LabelPosition::countFullOverlapCallback( LabelPosition *lp, void *ctx )
   LabelPosition *lp2 = context->lp;
   double *cost = context->cost;
   int *nbOv = context->nbOv;
-  double *inactiveCost = context->inactiveCost;
+  std::vector< double > &inactiveCost = *context->inactiveCost;
   if ( lp2->isInConflict( lp ) )
   {
     ( *nbOv ) ++;
diff --git a/src/core/pal/labelposition.h b/src/core/pal/labelposition.h
index 9519f2daf85..291a054e536 100644
--- a/src/core/pal/labelposition.h
+++ b/src/core/pal/labelposition.h
@@ -281,8 +281,7 @@ namespace pal
         LabelPosition *lp = nullptr;
         int *nbOv = nullptr;
         double *cost = nullptr;
-        double *inactiveCost = nullptr;
-        //int *feat;
+        std::vector< double > *inactiveCost = nullptr;
       };
 
       /*
diff --git a/src/core/pal/pal.cpp b/src/core/pal/pal.cpp
index 5bdbb05de0a..520e3c71b23 100644
--- a/src/core/pal/pal.cpp
+++ b/src/core/pal/pal.cpp
@@ -325,9 +325,9 @@ std::unique_ptr<Problem> Pal::extract( const QgsRectangle &extent, const QgsGeom
 
   prob->mFeatureCount = features.size();
   prob->mTotalCandidates = 0;
-  prob->mFeatNbLp = new int [prob->mFeatureCount];
-  prob->mFeatStartId = new int [prob->mFeatureCount];
-  prob->mInactiveCost = new double[prob->mFeatureCount];
+  prob->mFeatNbLp.resize( prob->mFeatureCount );
+  prob->mFeatStartId.resize( prob->mFeatureCount );
+  prob->mInactiveCost.resize( prob->mFeatureCount );
 
   if ( !features.empty() )
   {
diff --git a/src/core/pal/problem.cpp b/src/core/pal/problem.cpp
index b8ba4f0a73c..df9f4d36e39 100644
--- a/src/core/pal/problem.cpp
+++ b/src/core/pal/problem.cpp
@@ -57,13 +57,7 @@ inline void delete_chain( Chain *chain )
 
 Problem::Problem() = default;
 
-Problem::~Problem()
-{
-  delete[] mFeatStartId;
-  delete[] mFeatNbLp;
-
-  delete[] mInactiveCost;
-}
+Problem::~Problem() = default;
 
 void Problem::reduce()
 {
@@ -302,7 +296,7 @@ struct ChainContext
   QLinkedList<ElemTrans *> *currentChain;
   QLinkedList<int> *conflicts;
   double *delta_tmp = nullptr;
-  double *inactiveCost = nullptr;
+  std::vector< double > *inactiveCost = nullptr;
 
 } ;
 
@@ -346,7 +340,7 @@ bool chainCallback( LabelPosition *lp, void *context )
     if ( !ctx->conflicts->contains( feat ) )
     {
       ctx->conflicts->append( feat );
-      *ctx->delta_tmp += lp->cost() + ctx->inactiveCost[rfeat];
+      *ctx->delta_tmp += lp->cost() + ( * ctx->inactiveCost )[rfeat];
     }
   }
   return true;
@@ -386,7 +380,7 @@ inline Chain *Problem::chain( int seed )
   context.featWrap = nullptr;
   context.borderSize = 0;
   context.tmpsol = &tmpsol;
-  context.inactiveCost = mInactiveCost;
+  context.inactiveCost = &mInactiveCost;
   context.feat = nullptr;
   context.currentChain = &currentChain;
   context.conflicts = &conflicts;
@@ -786,7 +780,7 @@ void Problem::solution_cost()
   int nbOv;
 
   LabelPosition::CountContext context;
-  context.inactiveCost = mInactiveCost;
+  context.inactiveCost = &mInactiveCost;
   context.nbOv = &nbOv;
   context.cost = &mSol.totalCost;
   double amin[2];
diff --git a/src/core/pal/problem.h b/src/core/pal/problem.h
index d87220a4e2f..b8522f5029c 100644
--- a/src/core/pal/problem.h
+++ b/src/core/pal/problem.h
@@ -183,10 +183,9 @@ namespace pal
 
       std::vector< std::unique_ptr< LabelPosition > > mPositionsWithNoCandidates;
 
-      //int *feat;        // [nblp]
-      int *mFeatStartId = nullptr; // [nbft]
-      int *mFeatNbLp = nullptr;    // [nbft]
-      double *mInactiveCost = nullptr; //
+      std::vector< int > mFeatStartId;
+      std::vector< int > mFeatNbLp;
+      std::vector< double > mInactiveCost;
 
       class Sol
       {