diff --git a/src/BTCSBoundaryCondition.cpp b/src/BTCSBoundaryCondition.cpp
index eef46be..c45abd6 100644
--- a/src/BTCSBoundaryCondition.cpp
+++ b/src/BTCSBoundaryCondition.cpp
@@ -2,8 +2,8 @@
 #include <bits/stdint-uintn.h>
 #include <vector>
 
-#include "grid/BTCSBoundaryCondition.hpp"
 #include "BTCSUtils.hpp"
+#include "grid/BTCSBoundaryCondition.hpp"
 
 constexpr uint8_t DIM_1D = 2;
 constexpr uint8_t DIM_2D = 4;
@@ -126,10 +126,8 @@ auto Diffusion::BTCSBoundaryCondition::getInnerRow(uint32_t i) const -> bc_vec {
     throw_out_of_range("Index is out of range");
   }
 
-  bc_vec::const_iterator start =
-      this->special_cells.begin() + (i * this->sizes[Y_DIM]);
-  bc_vec::const_iterator end =
-      this->special_cells.begin() + ((i + 1) * this->sizes[Y_DIM]);
+  auto start = this->special_cells.begin() + (i * this->sizes[Y_DIM]);
+  auto end = this->special_cells.begin() + ((i + 1) * this->sizes[Y_DIM]);
 
   bc_vec row(start, end);
 
@@ -139,7 +137,8 @@ auto Diffusion::BTCSBoundaryCondition::getInnerRow(uint32_t i) const -> bc_vec {
 auto Diffusion::BTCSBoundaryCondition::getInnerCol(uint32_t i) const -> bc_vec {
   if (this->dim != 2) {
     throw_invalid_argument("getInnerCol is only applicable for 2D grids");
-  } else if (i >= this->sizes[X_DIM]) {
+  }
+  if (i >= this->sizes[X_DIM]) {
     throw_out_of_range("Index is out of range");
   }
 
diff --git a/src/BTCSDiffusion.cpp b/src/BTCSDiffusion.cpp
index 90d4354..9678b99 100644
--- a/src/BTCSDiffusion.cpp
+++ b/src/BTCSDiffusion.cpp
@@ -244,9 +244,10 @@ void Diffusion::BTCSDiffusion::fillMatrixFromRow(
   A_matrix.insert(0, 0) = 1;
 
   if (bc_inner[0].type != BC_UNSET) {
-    if (bc_inner[0].type != BC_TYPE_CONSTANT)
+    if (bc_inner[0].type != BC_TYPE_CONSTANT) {
       throw_invalid_argument("Inner boundary conditions with other type than "
                              "BC_TYPE_CONSTANT are currently not supported.");
+    }
     A_matrix.insert(1, 1) = 1;
   } else {
     sx = (alpha[0] * time_step) / (dx * dx);
@@ -257,9 +258,10 @@ void Diffusion::BTCSDiffusion::fillMatrixFromRow(
 
   for (int j = 2, k = j - 1; k < size - 1; j++, k++) {
     if (bc_inner[k].type != BC_UNSET) {
-      if (bc_inner[k].type != BC_TYPE_CONSTANT)
+      if (bc_inner[k].type != BC_TYPE_CONSTANT) {
         throw_invalid_argument("Inner boundary conditions with other type than "
                                "BC_TYPE_CONSTANT are currently not supported.");
+      }
       A_matrix.insert(j, j) = 1;
       continue;
     }
@@ -271,9 +273,10 @@ void Diffusion::BTCSDiffusion::fillMatrixFromRow(
   }
 
   if (bc_inner[size - 1].type != BC_UNSET) {
-    if (bc_inner[size - 1].type != BC_TYPE_CONSTANT)
+    if (bc_inner[size - 1].type != BC_TYPE_CONSTANT) {
       throw_invalid_argument("Inner boundary conditions with other type than "
                              "BC_TYPE_CONSTANT are currently not supported.");
+    }
     A_matrix.insert(A_size - 2, A_size - 2) = 1;
   } else {
     sx = (alpha[size - 1] * time_step) / (dx * dx);