diff --git a/opm/core/linalg/ParallelIstlInformation.hpp b/opm/core/linalg/ParallelIstlInformation.hpp
index 4a3504d44..80c2a6fc3 100644
--- a/opm/core/linalg/ParallelIstlInformation.hpp
+++ b/opm/core/linalg/ParallelIstlInformation.hpp
@@ -158,7 +158,7 @@ public:
                 }
             }
         }
-    };
+    }
     /// \brief Compute one or more global reductions.
     ///
     /// This function can either be used with a container, an operator, and an initial value
@@ -223,7 +223,6 @@ private:
         std::tuple<ReturnValues...> init=values;
         updateOwnerMask(std::get<0>(containers));
         computeLocalReduction(containers, operators, values);
-        auto val=std::get<0>(values);
         std::vector<std::tuple<ReturnValues...> > receivedValues(communicator_.size());
         communicator_.allgather(&values, 1, &(receivedValues[0]));
         values=init;
@@ -468,7 +467,9 @@ namespace Opm
 /// \param grid The grid to inspect.
 
 inline void extractParallelGridInformationToISTL(boost::any& anyComm, const UnstructuredGrid& grid)
-{}
+{
+    (void)anyComm; (void)grid;
+}
 } // end namespace Opm
 
 #endif
diff --git a/tests/DuneIstlTestHelpers.hpp b/tests/DuneIstlTestHelpers.hpp
index b13100f03..9335853da 100644
--- a/tests/DuneIstlTestHelpers.hpp
+++ b/tests/DuneIstlTestHelpers.hpp
@@ -56,7 +56,7 @@ struct MPIFixture {
 };
 
 
-BOOST_GLOBAL_FIXTURE(MPIFixture);
+BOOST_GLOBAL_FIXTURE(MPIFixture)
 
 struct MyMatrix
 {
@@ -177,7 +177,7 @@ void createRandomVectors(O& pinfo, int NN, std::vector<double>& x, std::vector<d
     pinfo.copyOwnerToAll(b,b);
 }
 
-std::tuple<int,int,int,int> computeRegions(int N=100)
+inline std::tuple<int,int,int,int> computeRegions(int N=100)
 {
     int procs, rank;
     MPI_Comm_rank(MPI_COMM_WORLD, &rank);