diff --git a/c_tools/mock/generateMock.cpp b/c_tools/mock/generateMock.cpp
index 5e93c3f..7f44b99 100644
--- a/c_tools/mock/generateMock.cpp
+++ b/c_tools/mock/generateMock.cpp
@@ -354,7 +354,8 @@ void createBox(SimuData *simu, vector<long>& targets, vector<long>& snapshot_spl
   for (int j = 0; j < 3; j++)
     {
       boxed->Pos[j] = new float[boxed->NumPart];
-      boxed->Vel[j] = 0;
+      boxed->Vel[j] = new float[boxed->NumPart];
+      //boxed->Vel[j] = 0;
       mul[j] = 1.0/(ranges[2*j+1] - ranges[2*j+0]);
     }
   cout << "Min range = " << ranges[0] << " " << ranges[2] << " " << ranges[4] << endl;
@@ -413,6 +414,7 @@ void buildBox(SimuData *simu, long num_targets, long loaded,
       for (int j = 0; j < 3; j++)
 	{
 	  boxed->Pos[j][loaded] = max(min((simu->Pos[j][pid]-ranges[j*2])*mul[j], double(1)), double(0));
+	  boxed->Vel[j][loaded] = simu->Vel[j][pid];
 	  assert(boxed->Pos[j][loaded] >= 0);
 	  assert(boxed->Pos[j][loaded] <= 1);
 	}
@@ -551,7 +553,8 @@ void makeBoxFromParameter(SimuData *simu, SimuData* &boxed, generateMock_info& a
   for (int j = 0; j < 3; j++)
     {
       boxed->Pos[j] = new float[boxed->NumPart];
-      boxed->Vel[j] = 0;
+      boxed->Vel[j] = new float[boxed->NumPart];
+      //boxed->Vel[j] = 0;
       mul[j] = 1.0/(ranges[2*j+1] - ranges[2*j+0]);
     }
   
diff --git a/c_tools/mock/loaders/multidark_loader.cpp b/c_tools/mock/loaders/multidark_loader.cpp
index 3d9c8a8..b9d0118 100644
--- a/c_tools/mock/loaders/multidark_loader.cpp
+++ b/c_tools/mock/loaders/multidark_loader.cpp
@@ -76,9 +76,10 @@ public:
     long estimated = (preproc == 0) ? simu->NumPart : preproc->getEstimatedPostprocessed(simu->NumPart);
     long allocated = estimated; 
 
-    for (int k = 0; k < 3; k++)
+    for (int k = 0; k < 3; k++) {
       simu->Pos[k] = new float[allocated];
-    simu->Vel[2] = new float[allocated];
+      simu->Vel[k] = new float[allocated];
+    }
     simu->Id = new long[allocated];
     long *uniqueID = new long[allocated];
     long *index = new long[allocated];
@@ -98,7 +99,7 @@ public:
       SingleParticle p;
 
       fp >> p.ID >> p.Pos[0] >> p.Pos[1]
-         >> p.Pos[2] >> p.Vel[2] >> tempData >> tempData >> tempData;
+         >> p.Pos[2] >> p.Vel[2] >> p.Vel[1] >> p.Vel[0] >> tempData;
 
       if (p.ID == -99 && 
           p.Pos[0] == -99 && p.Pos[1] == -99 &&