diff --git a/dumux/decoupled/2p/diffusion/fvmpfa/lmethod/fvmpfal2pfaboundpressure2p.hh b/dumux/decoupled/2p/diffusion/fvmpfa/lmethod/fvmpfal2pfaboundpressure2p.hh
index 37d35f9d21dd3d6c066e9a7c4212d30a1c1ad0dc..786b9563e6b0643dc0339e318e62511a8b8758dd 100644
--- a/dumux/decoupled/2p/diffusion/fvmpfa/lmethod/fvmpfal2pfaboundpressure2p.hh
+++ b/dumux/decoupled/2p/diffusion/fvmpfa/lmethod/fvmpfal2pfaboundpressure2p.hh
@@ -1703,7 +1703,7 @@ void FVMPFAL2PFABoundPressure2P<TypeTag>::assemble()
                 pcFluxReal[2] *= fracFlow34;
                 pcFluxReal[3] *= fracFlow14;
 
-//                if (isnan(pcFluxReal.two_norm()))
+//                if (std::isnan(pcFluxReal.two_norm()))
 //                                std::cout<<"pcFlux = "<<pcFlux<<"\n";
 
                 switch (pressureType_)
@@ -2249,7 +2249,7 @@ bool FVMPFAL2PFABoundPressure2P<TypeTag>::calculateTransmissibility(
     if (sR <= sL)
     {
         transmissibility = TR1;
-//        if (isnan(transmissibility.frobenius_norm()))
+//        if (std::isnan(transmissibility.frobenius_norm()))
 //        {
 //                    std::cout<<"right transmissibility = "<<transmissibility<<"\n";
 //                std::cout<<"globalPos1 = "<<globalPos1<<"\n";
@@ -2280,7 +2280,7 @@ bool FVMPFAL2PFABoundPressure2P<TypeTag>::calculateTransmissibility(
     else
     {
         transmissibility = TL1;
-//        if (isnan(transmissibility.frobenius_norm()))
+//        if (std::isnan(transmissibility.frobenius_norm()))
 //        {
 //                    std::cout<<"left transmissibility = "<<transmissibility<<"\n";
 //                std::cout<<"globalPos1 = "<<globalPos1<<"\n";
diff --git a/dumux/decoupled/2p2c/fvpressure2p2c.hh b/dumux/decoupled/2p2c/fvpressure2p2c.hh
index 14c3a0e2f23ea3b30b10e1dbec424698695ce4e1..b591e00364f60222892b53cbc05cfa26b45545ee 100644
--- a/dumux/decoupled/2p2c/fvpressure2p2c.hh
+++ b/dumux/decoupled/2p2c/fvpressure2p2c.hh
@@ -279,7 +279,7 @@ void FVPressure2P2C<TypeTag>::getStorage(Dune::FieldVector<Scalar, 2>& storageEn
         // the pressure Index used as a Primary Variable
         storageEntry[rhs] -= cellDataI.pressure(pressureType) * compress_term * volume;
 
-        if (isnan(compress_term) || isinf(compress_term))
+        if (std::isnan(compress_term) || std::isinf(compress_term))
             DUNE_THROW(Dune::MathError, "Compressibility term leads to NAN matrix entry at index " << globalIdxI);
 
         if(!GET_PROP_VALUE(TypeTag, EnableCompressibility))
diff --git a/dumux/decoupled/2p2c/fvpressure2p2cmultiphysics.hh b/dumux/decoupled/2p2c/fvpressure2p2cmultiphysics.hh
index dd8cf675f28bde5223ed6dc279dc24c24c78f4b6..07909c4f1ca0bfd172e3332fad1b93c88dd016c1 100644
--- a/dumux/decoupled/2p2c/fvpressure2p2cmultiphysics.hh
+++ b/dumux/decoupled/2p2c/fvpressure2p2cmultiphysics.hh
@@ -415,7 +415,7 @@ void FVPressure2P2CMultiPhysics<TypeTag>::get1pStorage(Dune::FieldVector<Scalar,
         storageEntry[matrix] -= compress_term*volume;
         storageEntry[rhs] -= cellDataI.pressure(pressureType) * compress_term * volume;
 
-        if (isnan(compress_term) || isinf(compress_term))
+        if (std::isnan(compress_term) || std::isinf(compress_term))
             DUNE_THROW(Dune::MathError, "Compressibility term leads to NAN matrix entry at index " << globalIdxI);
 
         if(!GET_PROP_VALUE(TypeTag, EnableCompressibility))
diff --git a/dumux/decoupled/2p2c/fvpressurecompositional.hh b/dumux/decoupled/2p2c/fvpressurecompositional.hh
index 37962a264b83c15ab53fc4f8b482ab9273a9f26f..0731c431b5f5fbbca7ffd6407e02fbc248a8feb0 100644
--- a/dumux/decoupled/2p2c/fvpressurecompositional.hh
+++ b/dumux/decoupled/2p2c/fvpressurecompositional.hh
@@ -770,7 +770,7 @@ void FVPressureCompositional<TypeTag>::volumeDerivatives(const GlobalPosition& g
         mass[compIdx] -= massIncrement[compIdx];
 
         //check routines if derivatives are meaningful
-        if (isnan(cellData.dv(compIdx)) || isinf(cellData.dv(compIdx)) )
+        if (std::isnan(cellData.dv(compIdx)) || std::isinf(cellData.dv(compIdx)) )
         {
             DUNE_THROW(Dune::MathError, "NAN/inf of dV_dm. If that happens in first timestep, try smaller firstDt!");
         }
diff --git a/dumux/linear/seqsolverbackend.hh b/dumux/linear/seqsolverbackend.hh
index 763d6fa1610a4f658a766d144916baeadd4cfe85..e5228106add951c23c7151c38cf13761ec2eb965 100644
--- a/dumux/linear/seqsolverbackend.hh
+++ b/dumux/linear/seqsolverbackend.hh
@@ -566,7 +566,7 @@ public:
     {
         for (int j = 0; j < blockSize; j++)
         {
-            if (isnan(x[i][j]) || isinf(x[i][j]))
+            if (std::isnan(x[i][j]) || std::isinf(x[i][j]))
             {
                 result_.converged = false;
                 break;