diff --git a/opm/core/wells/WellsGroup.cpp b/opm/core/wells/WellsGroup.cpp
index 5912f9994..db748e5ed 100644
--- a/opm/core/wells/WellsGroup.cpp
+++ b/opm/core/wells/WellsGroup.cpp
@@ -1353,6 +1353,7 @@ namespace Opm
                 case Phase::OIL:   return InjectionSpecification::OIL;
                 case Phase::WATER: return InjectionSpecification::WATER;
                 case Phase::GAS:   return InjectionSpecification::GAS;
+                case Phase::SOLVENT: OPM_THROW(std::invalid_argument, "Solvent injector is not supported.");
             }
             OPM_THROW(std::logic_error, "Invalid state." );
         }