diff --git a/MaterialLib/MPL/VariableType.cpp b/MaterialLib/MPL/VariableType.cpp
index 37086e0b74f55ca8f7ac39a70b0a7414124631b2..fee2bcf3764fbef3efb5e36eb44afe61ba5e23e6 100644
--- a/MaterialLib/MPL/VariableType.cpp
+++ b/MaterialLib/MPL/VariableType.cpp
@@ -17,6 +17,10 @@ namespace MaterialPropertyLib
 {
 Variable convertStringToVariable(std::string const& input)
 {
+    if (boost::iequals(input, "concentration"))
+    {
+        return Variable::concentration;
+    }
     if (boost::iequals(input, "phase_pressure"))
     {
         return Variable::phase_pressure;
diff --git a/MaterialLib/MPL/VariableType.h b/MaterialLib/MPL/VariableType.h
index e913af377007a101675bbbf9d2997cb4b55f5b3a..e11d51ba5335ad812e341278d9924dcfe96bc8d5 100644
--- a/MaterialLib/MPL/VariableType.h
+++ b/MaterialLib/MPL/VariableType.h
@@ -42,6 +42,7 @@ using Tensor = std::array<double, 9>;
 /// is missing, simply add it somewhere at the list, but above the last entry.
 enum class Variable : int
 {
+    concentration,
     phase_pressure,
     capillary_pressure,
     density,