diff --git a/src/OpenFOAM/meshes/polyMesh/mapPolyMesh/mapDistribute/mapDistribute.C b/src/OpenFOAM/meshes/polyMesh/mapPolyMesh/mapDistribute/mapDistribute.C
index f4cbe6e2f3..4bd093e641 100644
--- a/src/OpenFOAM/meshes/polyMesh/mapPolyMesh/mapDistribute/mapDistribute.C
+++ b/src/OpenFOAM/meshes/polyMesh/mapPolyMesh/mapDistribute/mapDistribute.C
@@ -205,7 +205,7 @@ Foam::mapDistribute::mapDistribute
     const labelList& recvProcs
 )
 :
-    constructSize_(sendProcs.size()),
+    constructSize_(0),
     schedulePtr_()
 {
     if (sendProcs.size() != recvProcs.size())
@@ -266,6 +266,8 @@ Foam::mapDistribute::mapDistribute
         {
             // I am the receiver.
             constructMap_[sendProc][nRecv[sendProc]++] = sampleI;
+            // Largest entry inside constructMap
+            constructSize_ = sampleI+1;
         }
     }
 }