diff --git a/src/ELECTRODE/electrode_matrix.cpp b/src/ELECTRODE/electrode_matrix.cpp
index efb92d7ef4..8dc9991885 100644
--- a/src/ELECTRODE/electrode_matrix.cpp
+++ b/src/ELECTRODE/electrode_matrix.cpp
@@ -90,7 +90,7 @@ void ElectrodeMatrix::compute_array(double **array, bool timer_flag)
   MPI_Barrier(world);
   double kspace_time = MPI_Wtime();
   update_mpos();
-  electrode_kspace->compute_matrix(&mpos[0], array, timer_flag);
+  electrode_kspace->compute_matrix(mpos.data(), array, timer_flag);
   MPI_Barrier(world);
   if (timer_flag && (comm->me == 0))
     utils::logmesg(lmp, "KSpace time: {:.4g} s\n", MPI_Wtime() - kspace_time);
@@ -98,7 +98,7 @@ void ElectrodeMatrix::compute_array(double **array, bool timer_flag)
   pair_contribution(array);
   //cout << array[0][0] << ", " << array[0][1] << endl;
   self_contribution(array);
-  electrode_kspace->compute_matrix_corr(&mpos[0], array);
+  electrode_kspace->compute_matrix_corr(mpos.data(), array);
   if (tfflag) tf_contribution(array);
 
   // reduce coulomb matrix with contributions from all procs
diff --git a/src/LATBOLTZ/fix_lb_fluid.cpp b/src/LATBOLTZ/fix_lb_fluid.cpp
index 4352e5ca18..7dbe0ed6aa 100644
--- a/src/LATBOLTZ/fix_lb_fluid.cpp
+++ b/src/LATBOLTZ/fix_lb_fluid.cpp
@@ -2425,9 +2425,9 @@ void FixLbFluid::dump(const bigint step)
             velocity_2_fort[2 + 3 * (i + (subNbx + 3) * (j + (subNby + 3) * k))] = u_lb[i][j][k][2];
           }
 
-      MPI_File_write_all(dump_file_handle_raw, &density_2_fort[0], 1, fluid_density_2_mpitype,
+      MPI_File_write_all(dump_file_handle_raw, density_2_fort.data(), 1, fluid_density_2_mpitype,
                          MPI_STATUS_IGNORE);
-      MPI_File_write_all(dump_file_handle_raw, &velocity_2_fort[0], 1, fluid_velocity_2_mpitype,
+      MPI_File_write_all(dump_file_handle_raw, velocity_2_fort.data(), 1, fluid_velocity_2_mpitype,
                          MPI_STATUS_IGNORE);
 
       // For C output use the following but switch to MPI_ORDER_C in mpiTypeXXXWrite
diff --git a/src/reader_native.cpp b/src/reader_native.cpp
index 567f37a0a0..fb59235c40 100644
--- a/src/reader_native.cpp
+++ b/src/reader_native.cpp
@@ -527,7 +527,7 @@ void ReaderNative::read_buf(void * ptr, size_t size, size_t count)
 std::string ReaderNative::read_binary_str(size_t size)
 {
   std::string str(size, '\0');
-  read_buf(&str[0], sizeof(char), size);
+  read_buf(str.data(), sizeof(char), size);
   return str;
 }