diff --git a/apps/calculation/app.cpp b/apps/calculation/app.cpp
index 25ccffc53..d13a71adc 100644
--- a/apps/calculation/app.cpp
+++ b/apps/calculation/app.cpp
@@ -6,6 +6,7 @@ namespace Calculation {
 App::App(Context * context) :
   ::App(&m_editExpressionController, "Calcul", ImageStore::CalculationIcon),
   m_globalContext(context),
+  m_evaluateContext(EvaluateContext(context, &m_calculationStore)),
   m_calculationStore(CalculationStore()),
   m_historyController(HistoryController(&m_editExpressionController, &m_calculationStore)),
   m_editExpressionController(EditExpressionController(&m_modalViewController, &m_historyController, &m_calculationStore, this))
@@ -16,4 +17,8 @@ Context * App::globalContext() {
   return m_globalContext;
 }
 
+Context * App::evaluateContext() {
+  return &m_evaluateContext;
+}
+
 }
diff --git a/apps/calculation/app.h b/apps/calculation/app.h
index 863fcfd8c..e4badd69c 100644
--- a/apps/calculation/app.h
+++ b/apps/calculation/app.h
@@ -2,6 +2,7 @@
 #define CALCULATION_APP_H
 
 #include "edit_expression_controller.h"
+#include "evaluate_context.h"
 #include "history_controller.h"
 #include "../expression_text_field_delegate.h"
 #include <escher.h>
@@ -12,8 +13,10 @@ class App : public ::App, public ExpressionTextFieldDelegate {
 public:
   App(Context * context);
   Context * globalContext();
+  Context * evaluateContext();
 private:
   Context * m_globalContext;
+  EvaluateContext m_evaluateContext;
   CalculationStore m_calculationStore;
   HistoryController m_historyController;
   EditExpressionController m_editExpressionController;
diff --git a/apps/calculation/edit_expression_controller.cpp b/apps/calculation/edit_expression_controller.cpp
index 45864ec15..1f6a6de0c 100644
--- a/apps/calculation/edit_expression_controller.cpp
+++ b/apps/calculation/edit_expression_controller.cpp
@@ -74,7 +74,7 @@ bool EditExpressionController::handleEvent(Ion::Events::Event event) {
     {
       Calculation calculation = Calculation();
       App * calculationApp = (App *)app();
-      calculation.setContent(textBody(), calculationApp->globalContext());
+      calculation.setContent(textBody(), calculationApp->evaluateContext());
       m_calculationStore->push(&calculation);
       m_historyController->reload();
       m_contentView.mainView()->scrollToCell(0, m_historyController->numberOfRows()-1);
diff --git a/apps/calculation/history_controller.cpp b/apps/calculation/history_controller.cpp
index 66051d5f3..190155d5c 100644
--- a/apps/calculation/history_controller.cpp
+++ b/apps/calculation/history_controller.cpp
@@ -69,7 +69,7 @@ bool HistoryController::handleEvent(Ion::Events::Event event) {
         char buffer[Constant::FloatBufferSizeInScientificMode];
         Float(calculation->evaluation()).convertFloatToText(buffer, Constant::FloatBufferSizeInScientificMode, Constant::NumberOfDigitsInMantissaInScientificMode);
         App * calculationApp = (App *)app();
-        newCalculation.setContent(buffer, calculationApp->globalContext());
+        newCalculation.setContent(buffer, calculationApp->evaluateContext());
       }
       m_selectableTableView.deselectTable();
       m_calculationStore->push(&newCalculation);