diff --git a/opm/core/grid/GridHelpers.hpp b/opm/core/grid/GridHelpers.hpp
index cb78562f..9ecb7727 100644
--- a/opm/core/grid/GridHelpers.hpp
+++ b/opm/core/grid/GridHelpers.hpp
@@ -190,10 +190,6 @@ const double* beginCellVolumes(const UnstructuredGrid& grid);
 /// \brief Get an iterator over the cell volumes of a grid positioned after the last cell.
 const double* endCellVolumes(const UnstructuredGrid& grid);
 
-/// \brief Get the cell centroid of a face.
-/// \param grid The grid whose cell centroid we query.
-/// \param face_index The index of the corresponding face.
-const double* faceCentroid(const UnstructuredGrid& grid, int face_index);
 
 
 /// \brief Traits of the face centroids of a grid.
@@ -220,7 +216,6 @@ beginFaceCentroids(const UnstructuredGrid& grid);
 /// \brief Get a coordinate of a specific face centroid.
 /// \param grid The grid.
 /// \param face_index The index of the specific face.
-/// \param coordinate The coordinate index.
 FaceCentroidTraits<UnstructuredGrid>::ValueType
 faceCentroid(const UnstructuredGrid& grid, int face_index);
 
diff --git a/opm/core/linalg/LinearSolverIstl.cpp b/opm/core/linalg/LinearSolverIstl.cpp
index 26a7102e..fa63e2fd 100644
--- a/opm/core/linalg/LinearSolverIstl.cpp
+++ b/opm/core/linalg/LinearSolverIstl.cpp
@@ -466,8 +466,8 @@ namespace Opm
                  double linsolver_prolongate_factor)
     {
         // Solve with AMG solver.
-        typedef Dune::MatrixAdapter<typename O::matrix_type, Vector, Vector> Operator;
-        Operator sOpA(opA.getmat());
+        typedef Dune::MatrixAdapter<typename O::matrix_type, Vector, Vector> AMGOperator;
+        AMGOperator sOpA(opA.getmat());
 
 #if FIRST_DIAGONAL
         typedef Dune::Amg::FirstDiagonal CouplingMetric;
@@ -482,7 +482,7 @@ namespace Opm
 #endif
 
         typedef Dune::Amg::CoarsenCriterion<CriterionBase> Criterion;
-        typedef Dune::Amg::FastAMG<Operator,Vector>   Precond;
+        typedef Dune::Amg::FastAMG<AMGOperator, Vector>   Precond;
 
         // Construct preconditioner.
         Criterion criterion;
diff --git a/opm/core/utility/Units.hpp b/opm/core/utility/Units.hpp
index 75bee386..55432717 100644
--- a/opm/core/utility/Units.hpp
+++ b/opm/core/utility/Units.hpp
@@ -35,6 +35,8 @@
 #ifndef OPM_UNITS_HEADER
 #define OPM_UNITS_HEADER
 
+
+
 /**
  * \file
  * Constants and routines to assist in handling units of measurement.  These are
@@ -216,6 +218,16 @@ namespace Opm
                 return q / unit;
             }
         } // namespace convert
+
+
+#ifndef HAS_ATTRIBUTE_UNUSED
+        namespace detail {
+            // Some units are sometimes unused, and generate a (potentially) large number of warnings
+            // Adding them here silences these warnings, and should have no side-effects
+            double __attribute__((unused)) unused_units = stb + liter + barsa + psia + darcy;
+        } // namespace detail
+#endif
+
     } // namespace unit
 } // namespace Opm
 #endif // OPM_UNITS_HEADER