diff --git a/opm/simulators/linalg/gpubridge/Reorder.cpp b/opm/simulators/linalg/gpubridge/Reorder.cpp
index 6422021041..65d56183ee 100644
--- a/opm/simulators/linalg/gpubridge/Reorder.cpp
+++ b/opm/simulators/linalg/gpubridge/Reorder.cpp
@@ -138,7 +138,7 @@ void csrPatternToCsc(const int* CSRColIndices,
     int nnz = CSRRowPointers[Nb];
 
     // compute number of nnzs per column
-    std::fill(CSCColPointers, CSCColPointers + Nb, 0);
+    std::fill_n(CSCColPointers, Nb, 0);
 
     for (int n = 0; n < nnz; ++n) {
         CSCColPointers[CSRColIndices[n]]++;
diff --git a/opm/simulators/wells/RateConverter.cpp b/opm/simulators/wells/RateConverter.cpp
index 0e3a1f6cb9..3cb26345a2 100644
--- a/opm/simulators/wells/RateConverter.cpp
+++ b/opm/simulators/wells/RateConverter.cpp
@@ -108,7 +108,7 @@ calcInjCoeff(const RegionId r, const int pvtRegionIdx, Coeff& coeff) const
     const int   io = phaseIdx<FluidSystem>(FluidSystem::oilPhaseIdx);
     const int   ig = phaseIdx<FluidSystem>(FluidSystem::gasPhaseIdx);
 
-    std::fill(& coeff[0], & coeff[0] + FluidSystem::numActivePhases(), 0.0);
+    std::fill_n(&coeff[0], FluidSystem::numActivePhases(), 0.0);
 
     if (FluidSystem::phaseIsActive(FluidSystem::waterPhaseIdx)) {
         // q[w]_r = q[w]_s / bw
@@ -184,7 +184,7 @@ calcCoeff(const int pvtRegionIdx,
     const int   io = phaseIdx<FluidSystem>(FluidSystem::oilPhaseIdx);
     const int   ig = phaseIdx<FluidSystem>(FluidSystem::gasPhaseIdx);
 
-    std::fill(& coeff[0], & coeff[0] + FluidSystem::numActivePhases(), 0.0);
+    std::fill_n(&coeff[0], FluidSystem::numActivePhases(), 0.0);
 
     // Determinant of 'R' matrix
     const Scalar detRw = 1.0 - (Rsw * Rvw);