diff --git a/opm/core/wells/WellsGroup.cpp b/opm/core/wells/WellsGroup.cpp
index 1e626a3d0..3f3ff9deb 100644
--- a/opm/core/wells/WellsGroup.cpp
+++ b/opm/core/wells/WellsGroup.cpp
@@ -1485,6 +1485,7 @@ namespace Opm
                 case Phase::POLYMER: OPM_THROW(std::invalid_argument, "Polymer injector is not supported.");
                 case Phase::ENERGY:  OPM_THROW(std::invalid_argument, "Energy injector is not supported.");
                 case Phase::POLYMW:  OPM_THROW(std::invalid_argument, "PolyMW injector is not supported.");
+                case Phase::FOAM:    OPM_THROW(std::invalid_argument, "Foam injector is not supported.");
             }
             OPM_THROW(std::logic_error, "Invalid state." );
         }