diff --git a/opm/simulators/wells/MultisegmentWellAssemble.cpp b/opm/simulators/wells/MultisegmentWellAssemble.cpp
index 79575e4e6..2a94144f1 100644
--- a/opm/simulators/wells/MultisegmentWellAssemble.cpp
+++ b/opm/simulators/wells/MultisegmentWellAssemble.cpp
@@ -352,7 +352,7 @@ assembleInflowTerm(const int seg,
 template<class FluidSystem, class Indices>
 void MultisegmentWellAssemble<FluidSystem,Indices>::
 assemblePerforationEq(const int seg,
-                      const int cell_idx,
+                      const int local_perf_index,
                       const int comp_idx,
                       const EvalWell& cq_s_effective,
                       Equations& eqns1) const
@@ -364,7 +364,7 @@ assemblePerforationEq(const int seg,
     // assemble the jacobians
     for (int pv_idx = 0; pv_idx < numWellEq; ++pv_idx) {
         // also need to consider the efficiency factor when manipulating the jacobians.
-        eqns.C()[seg][cell_idx][pv_idx][comp_idx] -= cq_s_effective.derivative(pv_idx + Indices::numEq); // input in transformed matrix
+        eqns.C()[seg][local_perf_index][pv_idx][comp_idx] -= cq_s_effective.derivative(pv_idx + Indices::numEq); // input in transformed matrix
 
         // the index name for the D should be eq_idx / pv_idx
         eqns.D()[seg][seg][comp_idx][pv_idx] += cq_s_effective.derivative(pv_idx + Indices::numEq);
@@ -372,7 +372,7 @@ assemblePerforationEq(const int seg,
 
     for (int pv_idx = 0; pv_idx < Indices::numEq; ++pv_idx) {
         // also need to consider the efficiency factor when manipulating the jacobians.
-        eqns.B()[seg][cell_idx][comp_idx][pv_idx] += cq_s_effective.derivative(pv_idx);
+        eqns.B()[seg][local_perf_index][comp_idx][pv_idx] += cq_s_effective.derivative(pv_idx);
     }
 }
 
diff --git a/opm/simulators/wells/MultisegmentWellAssemble.hpp b/opm/simulators/wells/MultisegmentWellAssemble.hpp
index 5ce922c72..7340fa7dd 100644
--- a/opm/simulators/wells/MultisegmentWellAssemble.hpp
+++ b/opm/simulators/wells/MultisegmentWellAssemble.hpp
@@ -139,7 +139,7 @@ public:
 
     //! \brief Assemble equation for a perforation.
     void assemblePerforationEq(const int seg,
-                               const int cell_idx,
+                               const int local_perf_index,
                                const int comp_idx,
                                const EvalWell& cq_s_effective,
                                Equations& eqns) const;