diff --git a/poincare/Makefile b/poincare/Makefile
index 42a7206a2..176b5ed3a 100644
--- a/poincare/Makefile
+++ b/poincare/Makefile
@@ -35,6 +35,7 @@ objs += $(addprefix poincare/src/,\
   layout_helper.o\
   simplification_helper.o\
   global_context.o\
+  variable_context.o\
 )
 
 objsExpected += $(addprefix poincare/src/,\
diff --git a/poincare/include/poincare/variable_context.h b/poincare/include/poincare/variable_context.h
index 60b4ad89e..a2726506d 100644
--- a/poincare/include/poincare/variable_context.h
+++ b/poincare/include/poincare/variable_context.h
@@ -2,7 +2,7 @@
 #define POINCARE_VARIABLE_CONTEXT_H
 
 #include <poincare/context.h>
-#include <poincare/approximation.h>
+#include <poincare/float.h>
 
 namespace Poincare {
 
@@ -11,11 +11,14 @@ class VariableContext : public Context {
 public:
   VariableContext(char name, Context * parentContext = nullptr);
   void setApproximationForVariable(T value);
-  void setExpressionForSymbolName(const Expression * expression, const Symbol * symbol, Context & context) override;
-  const Expression * expressionForSymbol(const Symbol * symbol) override;
+
+  // Context
+  void setExpressionForSymbolName(const Expression expression, const Symbol symbol, Context & context) override;
+  const Expression expressionForSymbol(const Symbol symbol) override;
+
 private:
   char m_name;
-  Approximation<T> m_value;
+  Float<T> m_value;
   Context * m_parentContext;
 };
 
diff --git a/poincare/src/variable_context.cpp b/poincare/src/variable_context.cpp
index dd92476bf..f3f202d8f 100644
--- a/poincare/src/variable_context.cpp
+++ b/poincare/src/variable_context.cpp
@@ -1,6 +1,7 @@
 #include <poincare/variable_context.h>
 #include <poincare/preferences.h>
-#include <assert.h>
+#include <poincare/symbol.h>
+
 #include <cmath>
 
 namespace Poincare {
@@ -8,32 +9,32 @@ namespace Poincare {
 template<typename T>
 VariableContext<T>::VariableContext(char name, Context * parentContext) :
   m_name(name),
-  m_value(Approximation<T>(NAN)),
+  m_value(Float<T>(NAN)),
   m_parentContext(parentContext)
 {
 }
 
 template<typename T>
 void VariableContext<T>::setApproximationForVariable(T value) {
-  m_value = Approximation<T>(value);
+  m_value = Float<T>(value);
 }
 
 template<typename T>
-void VariableContext<T>::setExpressionForSymbolName(const Expression * expression, const Symbol * symbol, Context & context) {
-  if (symbol->name() == m_name) {
-    if (expression == nullptr) {
+void VariableContext<T>::setExpressionForSymbolName(const Expression expression, const Symbol symbol, Context & context) {
+  if (symbol.name() == m_name) {
+    if (!expression.isDefined()) {
       return;
     }
-    m_value = Approximation<T>(expression->approximateToScalar<T>(context, Preferences::sharedPreferences()->angleUnit()));
+    m_value = Float<T>(expression.approximateToScalar<T>(context, Preferences::sharedPreferences()->angleUnit()));
   } else {
     m_parentContext->setExpressionForSymbolName(expression, symbol, context);
   }
 }
 
 template<typename T>
-const Expression * VariableContext<T>::expressionForSymbol(const Symbol * symbol) {
-  if (symbol->name() == m_name) {
-    return &m_value;
+const Expression VariableContext<T>::expressionForSymbol(const Symbol symbol) {
+  if (symbol.name() == m_name) {
+    return m_value;
   } else {
     return m_parentContext->expressionForSymbol(symbol);
   }