diff --git a/poincare/src/layout/bracket_layout.cpp b/poincare/src/layout/bracket_layout.cpp
index 32cdb10b0..c185fff75 100644
--- a/poincare/src/layout/bracket_layout.cpp
+++ b/poincare/src/layout/bracket_layout.cpp
@@ -47,22 +47,26 @@ bool BracketLayout::moveLeft(ExpressionLayoutCursor * cursor) {
 }
 
 void BracketLayout::render(KDContext * ctx, KDPoint p, KDColor expressionColor, KDColor backgroundColor) {
+  const KDCoordinate k_widthMargin = widthMargin();
+  const KDCoordinate k_externWidthMargin = externWidthMargin();
   KDSize operandSize = m_operandLayout->size();
-  ctx->fillRect(KDRect(p.x(), p.y(), k_lineThickness, m_operandLayout->size().height()), expressionColor);
-  ctx->fillRect(KDRect(p.x()+operandSize.width()+2*widthMargin()+k_lineThickness, p.y(), k_lineThickness, m_operandLayout->size().height()), expressionColor);
+  ctx->fillRect(KDRect(p.x()+k_externWidthMargin, p.y(), k_lineThickness, m_operandLayout->size().height()), expressionColor);
+  ctx->fillRect(KDRect(p.x()+k_externWidthMargin+operandSize.width()+2*k_widthMargin+k_lineThickness, p.y(), k_lineThickness, m_operandLayout->size().height()), expressionColor);
   if (renderTopBar()) {
-    ctx->fillRect(KDRect(p.x(), p.y(), k_bracketWidth, k_lineThickness), expressionColor);
-    ctx->fillRect(KDRect(p.x()+2*k_lineThickness+operandSize.width()+2*widthMargin()-k_bracketWidth, p.y(), k_bracketWidth, k_lineThickness), expressionColor);
+    ctx->fillRect(KDRect(p.x()+k_externWidthMargin, p.y(), k_bracketWidth, k_lineThickness), expressionColor);
+    ctx->fillRect(KDRect(p.x()+k_externWidthMargin+2*k_lineThickness+operandSize.width()+2*k_widthMargin-k_bracketWidth, p.y(), k_bracketWidth, k_lineThickness), expressionColor);
   }
   if (renderBottomBar()) {
-    ctx->fillRect(KDRect(p.x(), p.y()+operandSize.height()-k_lineThickness, k_bracketWidth, k_lineThickness), expressionColor);
-    ctx->fillRect(KDRect(p.x()+2*k_lineThickness+operandSize.width()+2*widthMargin()-k_bracketWidth, p.y()+operandSize.height()-k_lineThickness, k_bracketWidth, k_lineThickness), expressionColor);
+    ctx->fillRect(KDRect(p.x()+k_externWidthMargin, p.y()+operandSize.height()-k_lineThickness, k_bracketWidth, k_lineThickness), expressionColor);
+    ctx->fillRect(KDRect(p.x()+k_externWidthMargin+2*k_lineThickness+operandSize.width()+2*k_widthMargin-k_bracketWidth, p.y()+operandSize.height()-k_lineThickness, k_bracketWidth, k_lineThickness), expressionColor);
   }
 }
 
 KDSize BracketLayout::computeSize() {
+  const KDCoordinate k_widthMargin = widthMargin();
+  const KDCoordinate k_externWidthMargin = externWidthMargin();
   KDSize operandSize = m_operandLayout->size();
-  return KDSize(operandSize.width() + 2*widthMargin() + 2*k_lineThickness, operandSize.height());
+  return KDSize(operandSize.width() + 2*k_externWidthMargin + 2*k_widthMargin + 2*k_lineThickness, operandSize.height());
 }
 
 ExpressionLayout * BracketLayout::child(uint16_t index) {
@@ -73,7 +77,9 @@ ExpressionLayout * BracketLayout::child(uint16_t index) {
 }
 
 KDPoint BracketLayout::positionOfChild(ExpressionLayout * child) {
-  return KDPoint(widthMargin()+k_lineThickness, 0);
+  const KDCoordinate k_widthMargin = widthMargin();
+  const KDCoordinate k_externWidthMargin = externWidthMargin();
+  return KDPoint(k_widthMargin+k_externWidthMargin+k_lineThickness, 0);
 }
 
 }
diff --git a/poincare/src/layout/bracket_layout.h b/poincare/src/layout/bracket_layout.h
index 9016cb803..f110789aa 100644
--- a/poincare/src/layout/bracket_layout.h
+++ b/poincare/src/layout/bracket_layout.h
@@ -16,6 +16,7 @@ public:
   BracketLayout& operator=(BracketLayout&& other) = delete;
   bool moveLeft(ExpressionLayoutCursor * cursor) override;
 protected:
+  KDCoordinate externWidthMargin() const { return 2; }
   virtual KDCoordinate widthMargin() const { return 5; }
   virtual bool renderTopBar() const { return true; }
   virtual bool renderBottomBar() const { return true; }