diff --git a/opm/simulators/wells/StandardWellAssemble.cpp b/opm/simulators/wells/StandardWellAssemble.cpp
index 43af362b4..1e06f200e 100644
--- a/opm/simulators/wells/StandardWellAssemble.cpp
+++ b/opm/simulators/wells/StandardWellAssemble.cpp
@@ -81,9 +81,9 @@ private:
     StandardWellEquations<Scalar,numEq>& eqns_; //!< Reference to equation system
 };
 
-template<class FluidSystem, class Indices, class Scalar>
+template<class FluidSystem, class Indices>
 void
-StandardWellAssemble<FluidSystem,Indices,Scalar>::
+StandardWellAssemble<FluidSystem,Indices>::
 assembleControlEq(const WellState& well_state,
                   const GroupState& group_state,
                   const Schedule& schedule,
@@ -180,8 +180,8 @@ assembleControlEq(const WellState& well_state,
     }
 }
 
-template<class FluidSystem, class Indices, class Scalar>
-void StandardWellAssemble<FluidSystem,Indices,Scalar>::
+template<class FluidSystem, class Indices>
+void StandardWellAssemble<FluidSystem,Indices>::
 assembleInjectivityEq(const EvalWell& eq_pskin,
                       const EvalWell& eq_wat_vel,
                       const int pskin_index,
@@ -204,8 +204,8 @@ assembleInjectivityEq(const EvalWell& eq_pskin,
     }
 }
 
-template<class FluidSystem, class Indices, class Scalar>
-void StandardWellAssemble<FluidSystem,Indices,Scalar>::
+template<class FluidSystem, class Indices>
+void StandardWellAssemble<FluidSystem,Indices>::
 assemblePerforationEq(const EvalWell& cq_s_effective,
                       const int componentIdx,
                       const int cell_idx,
@@ -229,8 +229,8 @@ assemblePerforationEq(const EvalWell& cq_s_effective,
     }
 }
 
-template<class FluidSystem, class Indices, class Scalar>
-void StandardWellAssemble<FluidSystem,Indices,Scalar>::
+template<class FluidSystem, class Indices>
+void StandardWellAssemble<FluidSystem,Indices>::
 assembleSourceEq(const EvalWell& resWell_loc,
                  const int componentIdx,
                  const int numWellEq,
@@ -243,8 +243,8 @@ assembleSourceEq(const EvalWell& resWell_loc,
     eqns.residual()[0][componentIdx] += resWell_loc.value();
 }
 
-template<class FluidSystem, class Indices, class Scalar>
-void StandardWellAssemble<FluidSystem,Indices,Scalar>::
+template<class FluidSystem, class Indices>
+void StandardWellAssemble<FluidSystem,Indices>::
 assembleZFracEq(const EvalWell& cq_s_zfrac_effective,
                 const int cell_idx,
                 const int numWellEq,
@@ -257,7 +257,7 @@ assembleZFracEq(const EvalWell& cq_s_zfrac_effective,
 }
 
 #define INSTANCE(Dim,...) \
-template class StandardWellAssemble<BlackOilFluidSystem<double,BlackOilDefaultIndexTraits>,__VA_ARGS__,double>;
+template class StandardWellAssemble<BlackOilFluidSystem<double,BlackOilDefaultIndexTraits>,__VA_ARGS__>;
 
 // One phase
 INSTANCE(4u, BlackOilOnePhaseIndices<0u,0u,0u,0u,false,false,0u,1u,0u>)
diff --git a/opm/simulators/wells/StandardWellAssemble.hpp b/opm/simulators/wells/StandardWellAssemble.hpp
index 97107a50b..f5b6484ae 100644
--- a/opm/simulators/wells/StandardWellAssemble.hpp
+++ b/opm/simulators/wells/StandardWellAssemble.hpp
@@ -38,10 +38,11 @@ template<class FluidSystem> class WellInterfaceFluidSystem;
 class WellState;
 
 //! \brief Class handling assemble of the equation system for StandardWell.
-template<class FluidSystem, class Indices, class Scalar>
+template<class FluidSystem, class Indices>
 class StandardWellAssemble
 {
 public:
+    using Scalar = typename FluidSystem::Scalar;
     using PrimaryVariables = StandardWellPrimaryVariables<FluidSystem,Indices,Scalar>;
     using EvalWell = typename PrimaryVariables::EvalWell;
 
diff --git a/opm/simulators/wells/StandardWell_impl.hpp b/opm/simulators/wells/StandardWell_impl.hpp
index 45a8482f5..dbe2a61eb 100644
--- a/opm/simulators/wells/StandardWell_impl.hpp
+++ b/opm/simulators/wells/StandardWell_impl.hpp
@@ -398,7 +398,7 @@ namespace Opm
 
                 connectionRates[perf][componentIdx] = Base::restrictEval(cq_s_effective);
 
-                StandardWellAssemble<FluidSystem,Indices,Scalar>(*this).
+                StandardWellAssemble<FluidSystem,Indices>(*this).
                     assemblePerforationEq(cq_s_effective,
                                           componentIdx,
                                           cell_idx,
@@ -415,7 +415,7 @@ namespace Opm
             }
 
             if constexpr (has_zFraction) {
-                StandardWellAssemble<FluidSystem,Indices,Scalar>(*this).
+                StandardWellAssemble<FluidSystem,Indices>(*this).
                     assembleZFracEq(cq_s_zfrac_effective,
                                     cell_idx,
                                     this->primary_variables_.numWellEq(),
@@ -446,7 +446,7 @@ namespace Opm
                                 this->F0_[componentIdx]) * volume / dt;
             }
             resWell_loc -= this->primary_variables_.getQs(componentIdx) * this->well_efficiency_factor_;
-            StandardWellAssemble<FluidSystem,Indices,Scalar>(*this).
+            StandardWellAssemble<FluidSystem,Indices>(*this).
                 assembleSourceEq(resWell_loc,
                                  componentIdx,
                                  this->primary_variables_.numWellEq(),
@@ -455,7 +455,7 @@ namespace Opm
 
         const auto& summaryState = simulator.vanguard().summaryState();
         const Schedule& schedule = simulator.vanguard().schedule();
-        StandardWellAssemble<FluidSystem,Indices,Scalar>(*this).
+        StandardWellAssemble<FluidSystem,Indices>(*this).
             assembleControlEq(well_state, group_state,
                               schedule, summaryState,
                               inj_controls, prod_controls,
@@ -2075,7 +2075,7 @@ namespace Opm
         const EvalWell eq_pskin = this->primary_variables_.eval(pskin_index)
                                   - pskin(throughput, this->primary_variables_.eval(wat_vel_index), poly_conc, deferred_logger);
 
-        StandardWellAssemble<FluidSystem,Indices,Scalar>(*this).
+        StandardWellAssemble<FluidSystem,Indices>(*this).
                 assembleInjectivityEq(eq_pskin,
                                       eq_wat_vel,
                                       pskin_index,