diff --git a/dumux/material/components/iapws/region1.hh b/dumux/material/components/iapws/region1.hh
index 251e07af1cc014e2bc3cacfc766611215614b733..7d8e43e02bd6185c06a7d1253acf55f059e3c543 100644
--- a/dumux/material/components/iapws/region1.hh
+++ b/dumux/material/components/iapws/region1.hh
@@ -102,7 +102,7 @@ public:
         if (temperature <= 623.15 && pressure <= 100e6)
             return;
 
-        DUNE_THROW(Dune::NotImplemented,
+        DUNE_THROW(NumericalProblem,
                    propertyName << " of water is only implemented for temperatures below 623.15K and "
                    "pressures below 100MPa. (T=" << temperature << ", p=" << pressure << ")");
     }
diff --git a/dumux/material/components/iapws/region2.hh b/dumux/material/components/iapws/region2.hh
index cf223c9409017978a863309ae3fcc1a075715f50..206b98ca67f5985541cad87a6bc05f62d8f4e213 100644
--- a/dumux/material/components/iapws/region2.hh
+++ b/dumux/material/components/iapws/region2.hh
@@ -98,7 +98,7 @@ public:
         if (temperature <= 623.15 && pressure <= 100e6)
             return;
 
-        DUNE_THROW(Dune::NotImplemented,
+        DUNE_THROW(NumericalProblem,
                    propertyName << " of steam is only implemented for temperatures below 623.15K and "
                    "pressures below 100MPa. (T=" << temperature << ", p=" << pressure << ")");
     }