diff --git a/poincare/include/poincare/expression_layout.h b/poincare/include/poincare/expression_layout.h
index 485b34a92..6c6bdc114 100644
--- a/poincare/include/poincare/expression_layout.h
+++ b/poincare/include/poincare/expression_layout.h
@@ -107,7 +107,7 @@ public:
    * inserted in the numerator (or denominator)? For instance, 1+2|3-4 should
    * become 1+ 2/3 - 4 when pressing "Divide": a CharLayout is collapsable if
    * its char is not +, -, or *. */
-  bool canBeOmittedMultiplicationLeftFactor() const;
+  virtual bool canBeOmittedMultiplicationLeftFactor() const;
   virtual bool canBeOmittedMultiplicationRightFactor() const;
   /* canBeOmittedMultiplicationLeftFactor and RightFactor return true if the
    * layout, next to another layout, might be the factor of a multiplication
diff --git a/poincare/src/layout/char_layout.cpp b/poincare/src/layout/char_layout.cpp
index 0a4cd9018..15a4afed0 100644
--- a/poincare/src/layout/char_layout.cpp
+++ b/poincare/src/layout/char_layout.cpp
@@ -51,6 +51,7 @@ bool CharLayout::isCollapsable(int * numberOfOpenParenthesis, bool goingLeft) co
         || m_char == '*'
         || m_char == Ion::Charset::MultiplicationSign
         || m_char == Ion::Charset::MiddleDot
+        || m_char == Ion::Charset::Sto
         || m_char == ','))
   {
     return false;
@@ -58,6 +59,13 @@ bool CharLayout::isCollapsable(int * numberOfOpenParenthesis, bool goingLeft) co
   return true;
 }
 
+bool CharLayout::canBeOmittedMultiplicationLeftFactor() const {
+  return m_char != Ion::Charset::Sto;
+}
+bool CharLayout::canBeOmittedMultiplicationRightFactor() const {
+  return m_char != Ion::Charset::Sto;
+}
+
 void CharLayout::render(KDContext * ctx, KDPoint p, KDColor expressionColor, KDColor backgroundColor) {
   char string[2] = {m_char, 0};
   ctx->drawString(string, p, m_fontSize, expressionColor, backgroundColor);
diff --git a/poincare/src/layout/char_layout.h b/poincare/src/layout/char_layout.h
index 79da87bd2..93ccaf00b 100644
--- a/poincare/src/layout/char_layout.h
+++ b/poincare/src/layout/char_layout.h
@@ -28,6 +28,8 @@ public:
 
   // Other
   bool isCollapsable(int * numberOfOpenParenthesis, bool goingLeft) const override;
+  bool canBeOmittedMultiplicationLeftFactor() const override;
+  bool canBeOmittedMultiplicationRightFactor() const override;
 protected:
   void render(KDContext * ctx, KDPoint p, KDColor expressionColor, KDColor backgroundColor) override;
   KDPoint positionOfChild(ExpressionLayout * child) override {