diff --git a/apps/calculation/app.cpp b/apps/calculation/app.cpp
index 078dd77e4..48a60cb8d 100644
--- a/apps/calculation/app.cpp
+++ b/apps/calculation/app.cpp
@@ -97,7 +97,7 @@ bool App::textInputIsCorrect(const char * text) {
   }
   Expression::ReplaceSymbolWithExpression(&exp, Symbol::SpecialSymbols::Ans, static_cast<Snapshot *>(snapshot())->calculationStore()->ansExpression(localContext()));
   char buffer[Calculation::k_printedExpressionSize];
-  int length = PoincareHelpers::WriteTextInBuffer(exp, buffer, sizeof(buffer));
+  int length = PoincareHelpers::Serialize(exp, buffer, sizeof(buffer));
   delete exp;
   /* if the buffer is totally full, it is VERY likely that writeTextInBuffer
    * escaped before printing utterly the expression. */
diff --git a/apps/calculation/calculation.cpp b/apps/calculation/calculation.cpp
index 2c2badd93..098b602d0 100644
--- a/apps/calculation/calculation.cpp
+++ b/apps/calculation/calculation.cpp
@@ -60,11 +60,11 @@ void Calculation::setContent(const char * c, Context * context, Expression * ans
   Expression::ReplaceSymbolWithExpression(&m_input, Symbol::SpecialSymbols::Ans, ansExpression);
   /* We do not store directly the text enter by the user because we do not want
    * to keep Ans symbol in the calculation store. */
-  PoincareHelpers::WriteTextInBuffer(m_input, m_inputText, sizeof(m_inputText));
+  PoincareHelpers::Serialize(m_input, m_inputText, sizeof(m_inputText));
   m_exactOutput = PoincareHelpers::ParseAndSimplify(m_inputText, *context);
-  PoincareHelpers::WriteTextInBuffer(m_exactOutput, m_exactOutputText, sizeof(m_exactOutputText));
+  PoincareHelpers::Serialize(m_exactOutput, m_exactOutputText, sizeof(m_exactOutputText));
   m_approximateOutput = PoincareHelpers::Approximate<double>(m_exactOutput, *context);
-  PoincareHelpers::WriteTextInBuffer(m_approximateOutput, m_approximateOutputText, sizeof(m_approximateOutputText));
+  PoincareHelpers::Serialize(m_approximateOutput, m_approximateOutputText, sizeof(m_approximateOutputText));
 }
 
 KDCoordinate Calculation::height(Context * context) {
diff --git a/apps/shared/poincare_helpers.h b/apps/shared/poincare_helpers.h
index aad71c9a5..e3b1bc4c9 100644
--- a/apps/shared/poincare_helpers.h
+++ b/apps/shared/poincare_helpers.h
@@ -7,8 +7,8 @@ namespace Shared {
 
 namespace PoincareHelpers {
 
-inline Poincare::LayoutRef CreateLayout(const Poincare::Expression * e)  {
-  return e->createLayout(Poincare::Preferences::sharedPreferences()->displayMode(), Poincare::Preferences::sharedPreferences()->numberOfSignificantDigits());
+inline Poincare::LayoutRef CreateLayout(const Poincare::Expression e)  {
+  return e.createLayout(Poincare::Preferences::sharedPreferences()->displayMode(), Poincare::Preferences::sharedPreferences()->numberOfSignificantDigits());
 }
 
 template <class T>
@@ -16,18 +16,18 @@ inline int ConvertFloatToText(T d, char * buffer, int bufferSize, int numberOfSi
   return Poincare::PrintFloat::convertFloatToText(d, buffer, bufferSize, numberOfSignificantDigits, Poincare::Preferences::sharedPreferences()->displayMode());
 }
 
-inline int WriteTextInBuffer(const Poincare::Expression * e, char * buffer, int bufferSize, int numberOfSignificantDigits = Poincare::PrintFloat::k_numberOfStoredSignificantDigits) {
-  return e->serialize(buffer, bufferSize, Poincare::Preferences::sharedPreferences()->displayMode(), numberOfSignificantDigits);
+inline int Serialize(const Poincare::Expression e, char * buffer, int bufferSize, int numberOfSignificantDigits = Poincare::PrintFloat::k_numberOfStoredSignificantDigits) {
+  return e.serialize(buffer, bufferSize, Poincare::Preferences::sharedPreferences()->displayMode(), numberOfSignificantDigits);
 }
 
 template <class T>
-inline Poincare::Expression * Approximate(const Poincare::Expression * e, Poincare::Context & context) {
-  return e->approximate<T>(context, Poincare::Preferences::sharedPreferences()->angleUnit(), Poincare::Preferences::sharedPreferences()->complexFormat());
+inline Poincare::Expression Approximate(const Poincare::Expression e, Poincare::Context & context) {
+  return e.approximate<T>(context, Poincare::Preferences::sharedPreferences()->angleUnit(), Poincare::Preferences::sharedPreferences()->complexFormat());
 }
 
 template <class T>
-inline T ApproximateToScalar(const Poincare::Expression * e, Poincare::Context & context) {
-  return e->approximateToScalar<T>(context, Poincare::Preferences::sharedPreferences()->angleUnit());
+inline T ApproximateToScalar(const Poincare::Expression e, Poincare::Context & context) {
+  return e.approximateToScalar<T>(context, Poincare::Preferences::sharedPreferences()->angleUnit());
 }
 
 template <class T>
@@ -35,11 +35,11 @@ inline T ApproximateToScalar(const char * text, Poincare::Context & context) {
   return Poincare::Expression::approximateToScalar<T>(text, context, Poincare::Preferences::sharedPreferences()->angleUnit());
 }
 
-inline Poincare::Expression * ParseAndSimplify(const char * text, Poincare::Context & context) {
+inline Poincare::Expression ParseAndSimplify(const char * text, Poincare::Context & context) {
   return Poincare::Expression::ParseAndSimplify(text, context, Poincare::Preferences::sharedPreferences()->angleUnit());
 }
 
-inline void Simplify(Poincare::Expression ** expressionAddress, Poincare::Context & context) {
+inline void Simplify(Poincare::Expression* expressionAddress, Poincare::Context & context) {
   return Poincare::Expression::Simplify(expressionAddress, context, Poincare::Preferences::sharedPreferences()->angleUnit());
 }
 
diff --git a/apps/variable_box_controller.cpp b/apps/variable_box_controller.cpp
index 4c34e1752..6686ed4cd 100644
--- a/apps/variable_box_controller.cpp
+++ b/apps/variable_box_controller.cpp
@@ -142,7 +142,7 @@ void VariableBoxController::ContentViewController::willDisplayCellForIndex(Highl
   if (m_currentPage == Page::Scalar) {
     myCell->displayExpression(false);
     char buffer[PrintFloat::k_maxComplexBufferLength];
-    PoincareHelpers::WriteTextInBuffer(evaluation, buffer, PrintFloat::k_maxComplexBufferLength, Constant::ShortNumberOfSignificantDigits);
+    PoincareHelpers::Serialize(evaluation, buffer, PrintFloat::k_maxComplexBufferLength, Constant::ShortNumberOfSignificantDigits);
     myCell->setSubtitle(buffer);
     return;
   }