diff --git a/opm/autodiff/BlackoilDetails.hpp b/opm/autodiff/BlackoilDetails.hpp
index feb4ed37f..411fe9dd1 100644
--- a/opm/autodiff/BlackoilDetails.hpp
+++ b/opm/autodiff/BlackoilDetails.hpp
@@ -156,6 +156,48 @@ namespace detail {
             }
         }
 
+        /// \brief Get the number of local interior cells in a grid.
+        /// \tparam The type of the DUNE grid.
+        /// \param grid The grid which cells we count
+        /// \return The number of interior cell in the partition of the
+        /// grid stored on this process.
+        template<class Grid>
+        std::size_t countLocalInteriorCells(const Grid& grid)
+        {
+            if ( grid.comm().size() == 1)
+            {
+                return grid.size(0);
+            }
+            std::size_t count = 0;
+            const auto& gridView = grid.leafGridView();
+            for(auto cell = gridView.template begin<0, Dune::Interior_Partition>(),
+                    endCell = gridView.template end<0, Dune::Interior_Partition>();
+                cell != endCell; ++cell)
+            {
+                    ++count;
+            }
+            return count;
+        }
+
+        /// \brief Get the number of cells of a global grid.
+        ///
+        /// In a parallel run this is the number of cells that a grid would
+        /// have if the whole grid was stored on one process only.
+        /// \tparam The type of the DUNE grid.
+        /// \param grid The grid which cells we count
+        /// \return The global number of cells.
+        template<class Grid>
+        std::size_t countGlobalCells(const Grid& grid)
+        {
+            if ( grid.comm().size() == 1)
+            {
+                return grid.size(0);
+            }
+            std::size_t count = countLocalInteriorCells(grid);
+            return grid.comm().sum(count);
+        }
+
+
         template <class Scalar>
         inline
         double
diff --git a/opm/autodiff/BlackoilModelEbos.hpp b/opm/autodiff/BlackoilModelEbos.hpp
index 5df798688..5b60c4bcd 100644
--- a/opm/autodiff/BlackoilModelEbos.hpp
+++ b/opm/autodiff/BlackoilModelEbos.hpp
@@ -190,9 +190,8 @@ namespace Opm {
             const std::vector<double> depth(geo_.z().data(), geo_.z().data() + geo_.z().size());
             well_model_.init(fluid_.phaseUsage(), active_, &vfp_properties_, gravity, depth, pv, &rate_converter_);
             wellModel().setWellsActive( localWellsActive() );
-            global_nc_ =  Opm::AutoDiffGrid::numCells(grid_);
             // compute global sum of number of cells
-            global_nc_ = grid_.comm().sum( global_nc_ );
+            global_nc_ = detail::countGlobalCells(grid_);
 
             if (!istlSolver_)
             {