diff --git a/opm/simulators/wells/StandardWellConnections.cpp b/opm/simulators/wells/StandardWellConnections.cpp
index 4925f188a7..a6fe6f7d8d 100644
--- a/opm/simulators/wells/StandardWellConnections.cpp
+++ b/opm/simulators/wells/StandardWellConnections.cpp
@@ -430,7 +430,7 @@ computeDensitiesForStoppedProducer(const DensityPropertyFunctions& prop_func)
         auto phIx = std::vector<int>(np);
 
         for (auto p = 0*np; p < np; ++p) {
-            phIx[p] = this->well_.flowPhaseToModelPhaseIdx(p);
+            phIx[p] = FluidSystem::activeToCanonicalPhaseIdx(p);
         }
 
         return phIx;
diff --git a/opm/simulators/wells/WellInterfaceIndices.cpp b/opm/simulators/wells/WellInterfaceIndices.cpp
index 7ef4598fe9..880933dea0 100644
--- a/opm/simulators/wells/WellInterfaceIndices.cpp
+++ b/opm/simulators/wells/WellInterfaceIndices.cpp
@@ -99,26 +99,6 @@ modelCompIdxToFlowPhaseIdx(const int compIdx) const
 }
 
 
-template<typename FluidSystem, class Indices>
-int
-WellInterfaceIndices<FluidSystem, Indices>::
-flowPhaseToModelPhaseIdx(const int phaseIdx) const
-{
-    if (FluidSystem::phaseIsActive(FluidSystem::waterPhaseIdx) &&
-            FluidSystem::canonicalToActivePhaseIdx(FluidSystem::waterPhaseIdx) == phaseIdx)
-        return FluidSystem::waterPhaseIdx;
-    if (FluidSystem::phaseIsActive(FluidSystem::oilPhaseIdx) &&
-            FluidSystem::canonicalToActivePhaseIdx(FluidSystem::oilPhaseIdx) == phaseIdx)
-        return FluidSystem::oilPhaseIdx;
-    if (FluidSystem::phaseIsActive(FluidSystem::gasPhaseIdx) &&
-            FluidSystem::canonicalToActivePhaseIdx(FluidSystem::gasPhaseIdx) == phaseIdx)
-        return FluidSystem::gasPhaseIdx;
-
-    // for other phases return the index
-    return phaseIdx;
-}
-
-
 template<class FluidSystem, class Indices>
 typename WellInterfaceIndices<FluidSystem,Indices>::Scalar
 WellInterfaceIndices<FluidSystem,Indices>::
diff --git a/opm/simulators/wells/WellInterfaceIndices.hpp b/opm/simulators/wells/WellInterfaceIndices.hpp
index 50bc8aa1d8..caa1a53f46 100644
--- a/opm/simulators/wells/WellInterfaceIndices.hpp
+++ b/opm/simulators/wells/WellInterfaceIndices.hpp
@@ -42,7 +42,6 @@ public:
 
     int flowPhaseToModelCompIdx(const int phaseIdx) const;
     int modelCompIdxToFlowPhaseIdx(const int compIdx) const;
-    int flowPhaseToModelPhaseIdx(const int phaseIdx) const;
     Scalar scalingFactor(const int phaseIdx) const;
 
     template <class EvalWell>
diff --git a/opm/simulators/wells/WellInterface_impl.hpp b/opm/simulators/wells/WellInterface_impl.hpp
index a951811379..96ed48b032 100644
--- a/opm/simulators/wells/WellInterface_impl.hpp
+++ b/opm/simulators/wells/WellInterface_impl.hpp
@@ -1606,12 +1606,12 @@ namespace Opm
             const Scalar well_tw_fraction = this->well_index_[perf] / total_tw;
             Scalar total_mobility = 0.0;
             for (int p = 0; p < np; ++p) {
-                int modelPhaseIdx = this->flowPhaseToModelPhaseIdx(p);
-                total_mobility += fs.invB(modelPhaseIdx).value() * intQuants.mobility(modelPhaseIdx).value();
+                const int canonical_phase_idx = FluidSystem::activeToCanonicalPhaseIdx(p);
+                total_mobility += fs.invB(canonical_phase_idx).value() * intQuants.mobility(canonical_phase_idx).value();
             }
             for (int p = 0; p < np; ++p) {
-                int modelPhaseIdx = this->flowPhaseToModelPhaseIdx(p);
-                scaling_factor[p] += well_tw_fraction * fs.invB(modelPhaseIdx).value() * intQuants.mobility(modelPhaseIdx).value() / total_mobility;
+                const int canonical_phase_idx = FluidSystem::activeToCanonicalPhaseIdx(p);
+                scaling_factor[p] += well_tw_fraction * fs.invB(canonical_phase_idx).value() * intQuants.mobility(canonical_phase_idx).value() / total_mobility;
             }
         }
         return scaling_factor;
@@ -2014,9 +2014,9 @@ namespace Opm
         for (int p = 0; p < np; ++p) {
             // Note: E100's notion of PI value phase mobility includes
             // the reciprocal FVF.
+            const int canonical_phase_idx = FluidSystem::activeToCanonicalPhaseIdx(p);
             const auto connMob =
-                mobility[this->flowPhaseToModelCompIdx(p)]
-                    * fs.invB(this->flowPhaseToModelPhaseIdx(p)).value();
+                mobility[this->flowPhaseToModelCompIdx(p)] * fs.invB(canonical_phase_idx).value();
 
             connPI[p] = connPICalc(connMob);
         }
@@ -2065,7 +2065,8 @@ namespace Opm
         }
 
         const auto mt     = std::accumulate(mobility.begin(), mobility.end(), 0.0);
-        connII[phase_pos] = connIICalc(mt * fs.invB(this->flowPhaseToModelPhaseIdx(phase_pos)).value());
+        const int canonicalPhseIdx = FluidSystem::activeToCanonicalPhaseIdx(phase_pos);
+        connII[phase_pos] = connIICalc(mt * fs.invB(canonicalPhseIdx).value());
     }
 
     template<typename TypeTag>