diff --git a/apps/graph/graph/graph_controller.cpp b/apps/graph/graph/graph_controller.cpp
index 93aff8660..0c2e5f3c4 100644
--- a/apps/graph/graph/graph_controller.cpp
+++ b/apps/graph/graph/graph_controller.cpp
@@ -41,7 +41,7 @@ float GraphController::interestingXRange() {
   float characteristicRange = 0.0f;
   TextFieldDelegateApp * myApp = (TextFieldDelegateApp *)app();
   for (int i = 0; i < functionStore()->numberOfActiveFunctions(); i++) {
-    StorageFunction * f = functionStore()->modelForRecord(functionStore()->activeRecordAtIndex(i));
+    ExpiringPointer<StorageCartesianFunction> f = functionStore()->modelForRecord(functionStore()->activeRecordAtIndex(i));
     float fRange = f->expression(myApp->localContext()).characteristicXRange(*(myApp->localContext()), Poincare::Preferences::sharedPreferences()->angleUnit());
     if (!std::isnan(fRange)) {
       characteristicRange = fRange > characteristicRange ? fRange : characteristicRange;
@@ -56,7 +56,7 @@ int GraphController::estimatedBannerNumberOfLines() const {
 
 void GraphController::selectFunctionWithCursor(int functionIndex) {
   StorageFunctionGraphController::selectFunctionWithCursor(functionIndex);
-  StorageCartesianFunction * f = functionStore()->modelForRecord(functionStore()->activeRecordAtIndex(indexFunctionSelectedByCursor()));
+  ExpiringPointer<StorageCartesianFunction> f = functionStore()->modelForRecord(functionStore()->activeRecordAtIndex(indexFunctionSelectedByCursor()));
   m_cursorView.setColor(f->color());
 }
 
diff --git a/apps/graph/graph/graph_controller_helper.cpp b/apps/graph/graph/graph_controller_helper.cpp
index 67f52f61d..41ca6250c 100644
--- a/apps/graph/graph/graph_controller_helper.cpp
+++ b/apps/graph/graph/graph_controller_helper.cpp
@@ -9,7 +9,7 @@ using namespace Poincare;
 namespace Graph {
 
 bool GraphControllerHelper::privateMoveCursorHorizontally(Shared::CurveViewCursor * cursor, int direction, Shared::InteractiveCurveViewRange * range, int numberOfStepsInGradUnit, Ion::Storage::Record record, App * app, float cursorTopMarginRatio, float cursorRightMarginRatio, float cursorBottomMarginRatio, float cursorLeftMarginRatio) {
-  StorageCartesianFunction * function = app->functionStore()->modelForRecord(record);
+  ExpiringPointer<StorageCartesianFunction> function = app->functionStore()->modelForRecord(record);
   double xCursorPosition = cursor->x();
   double x = direction > 0 ? xCursorPosition + range->xGridUnit()/numberOfStepsInGradUnit : xCursorPosition -  range->xGridUnit()/numberOfStepsInGradUnit;
   double y = function->evaluateAtAbscissa(x, app->localContext());
@@ -19,7 +19,7 @@ bool GraphControllerHelper::privateMoveCursorHorizontally(Shared::CurveViewCurso
 }
 
 void GraphControllerHelper::reloadDerivativeInBannerViewForCursorOnFunction(Shared::CurveViewCursor * cursor, Ion::Storage::Record record, App * app) {
-  StorageCartesianFunction * function = app->functionStore()->modelForRecord(record);
+  ExpiringPointer<StorageCartesianFunction> function = app->functionStore()->modelForRecord(record);
   constexpr size_t bufferSize = FunctionBannerDelegate::k_maxNumberOfCharacters+PrintFloat::bufferSizeForFloatsWithPrecision(Constant::LargeNumberOfSignificantDigits);
   char buffer[bufferSize];
   const char * space = " ";
diff --git a/apps/graph/graph/graph_view.cpp b/apps/graph/graph/graph_view.cpp
index 2d04cfb40..be44101ab 100644
--- a/apps/graph/graph/graph_view.cpp
+++ b/apps/graph/graph/graph_view.cpp
@@ -25,7 +25,7 @@ void GraphView::drawRect(KDContext * ctx, KDRect rect) const {
   StorageFunctionGraphView::drawRect(ctx, rect);
   for (int i = 0; i < m_functionStore->numberOfActiveFunctions(); i++) {
     Ion::Storage::Record record = m_functionStore->activeRecordAtIndex(i);
-    StorageCartesianFunction * f = m_functionStore->modelForRecord(record);;
+    ExpiringPointer<StorageCartesianFunction> f = m_functionStore->modelForRecord(record);;
 
     /* Draw function (color the area under curve of the selected function) */
     if (record == m_selectedRecord) {
@@ -33,13 +33,13 @@ void GraphView::drawRect(KDContext * ctx, KDRect rect) const {
         StorageCartesianFunction * f = (StorageCartesianFunction *)model;
         Poincare::Context * c = (Poincare::Context *)context;
         return f->evaluateAtAbscissa(t, c);
-      }, f, context(), f->color(), true, m_highlightedStart, m_highlightedEnd);
+      }, f.operator->(), context(), f->color(), true, m_highlightedStart, m_highlightedEnd);
     } else {
       drawCurve(ctx, rect, [](float t, void * model, void * context) {
         StorageCartesianFunction * f = (StorageCartesianFunction *)model;
         Poincare::Context * c = (Poincare::Context *)context;
         return f->evaluateAtAbscissa(t, c);
-      }, f, context(), f->color());
+      }, f.operator->(), context(), f->color());
     }
 
     /* Draw tangent */
diff --git a/apps/graph/graph/integral_graph_controller.cpp b/apps/graph/graph/integral_graph_controller.cpp
index 2ce449b95..a2ff51402 100644
--- a/apps/graph/graph/integral_graph_controller.cpp
+++ b/apps/graph/graph/integral_graph_controller.cpp
@@ -36,7 +36,7 @@ double IntegralGraphController::cursorNextStep(double x, int direction) {
   return (direction > 0 ? x + m_graphRange->xGridUnit()/k_numberOfCursorStepsInGradUnit : x - m_graphRange->xGridUnit()/k_numberOfCursorStepsInGradUnit);
 }
 
-Layout IntegralGraphController::createFunctionLayout(StorageFunction * function) {
+Layout IntegralGraphController::createFunctionLayout(ExpiringPointer<StorageFunction> function) {
   constexpr size_t bufferSize = SymbolAbstract::k_maxNameSize+5; // f(x)dx
   char buffer[bufferSize];
   const char * dx = "dx";
diff --git a/apps/graph/graph/integral_graph_controller.h b/apps/graph/graph/integral_graph_controller.h
index 67f56fb00..cc0d6f663 100644
--- a/apps/graph/graph/integral_graph_controller.h
+++ b/apps/graph/graph/integral_graph_controller.h
@@ -14,7 +14,7 @@ public:
 private:
   I18n::Message legendMessageAtStep(Step step) override;
   double cursorNextStep(double position, int direction) override;
-  Poincare::Layout createFunctionLayout(Shared::StorageFunction * function) override;
+  Poincare::Layout createFunctionLayout(Shared::ExpiringPointer<Shared::StorageFunction> function) override;
 };
 
 }
diff --git a/apps/graph/graph/intersection_graph_controller.cpp b/apps/graph/graph/intersection_graph_controller.cpp
index a39f7c7a3..3b2638510 100644
--- a/apps/graph/graph/intersection_graph_controller.cpp
+++ b/apps/graph/graph/intersection_graph_controller.cpp
@@ -24,11 +24,11 @@ void IntersectionGraphController::reloadBannerView() {
   const char * space = "                  ";
   const char * legend = "=";
   // 'f(x)=g(x)=', keep 2 chars for '='
-  StorageCartesianFunction * f = functionStore()->modelForRecord(m_record);
+  ExpiringPointer<StorageCartesianFunction> f = functionStore()->modelForRecord(m_record);
   int numberOfChar = f->nameWithArgument(buffer, bufferSize-2, StorageCartesianFunctionStore::Symbol());
   numberOfChar += strlcpy(buffer+numberOfChar, legend, bufferSize-numberOfChar);
   // keep 1 char for '=';
-  StorageCartesianFunction * g = functionStore()->modelForRecord(m_intersectedRecord);
+  ExpiringPointer<StorageCartesianFunction> g = functionStore()->modelForRecord(m_intersectedRecord);
   numberOfChar += g->nameWithArgument(buffer, bufferSize-numberOfChar-1, StorageCartesianFunctionStore::Symbol());
   numberOfChar += strlcpy(buffer+numberOfChar, legend, bufferSize-numberOfChar);
   numberOfChar += PoincareHelpers::ConvertFloatToText<double>(m_cursor->y(), buffer+numberOfChar, bufferSize-numberOfChar, Constant::MediumNumberOfSignificantDigits);
diff --git a/apps/graph/graph/tangent_graph_controller.cpp b/apps/graph/graph/tangent_graph_controller.cpp
index 9f6a01c1e..b3ab42e99 100644
--- a/apps/graph/graph/tangent_graph_controller.cpp
+++ b/apps/graph/graph/tangent_graph_controller.cpp
@@ -46,7 +46,7 @@ void TangentGraphController::reloadBannerView() {
   char buffer[bufferSize];
   const char * legend = "a=";
   int legendLength = strlcpy(buffer, legend, bufferSize);
-  StorageCartesianFunction * function = myApp->functionStore()->modelForRecord(m_record);
+  ExpiringPointer<StorageCartesianFunction> function = myApp->functionStore()->modelForRecord(m_record);
   double y = function->approximateDerivative(m_cursor->x(), myApp->localContext());
   PoincareHelpers::ConvertFloatToText<double>(y, buffer + legendLength, PrintFloat::bufferSizeForFloatsWithPrecision(Constant::MediumNumberOfSignificantDigits), Constant::MediumNumberOfSignificantDigits);
   m_bannerView->setLegendAtIndex(buffer, 4);
diff --git a/apps/graph/list/storage_list_controller.cpp b/apps/graph/list/storage_list_controller.cpp
index 61b3cd080..7c747a2d1 100644
--- a/apps/graph/list/storage_list_controller.cpp
+++ b/apps/graph/list/storage_list_controller.cpp
@@ -92,7 +92,7 @@ bool StorageListController::textFieldDidFinishEditing(TextField * textField, con
 }
 
 bool StorageListController::textFieldDidAbortEditing(TextField * textField) {
-  StorageFunction * function = modelStore()->modelForRecord(modelStore()->recordAtIndex(selectedRow()));
+  ExpiringPointer<StorageFunction> function = modelStore()->modelForRecord(modelStore()->recordAtIndex(selectedRow()));
   setFunctionNameInTextField(function, textField);
   m_selectableTableView.selectedCell()->setHighlighted(true);
   app()->setFirstResponder(&m_selectableTableView);
@@ -124,7 +124,7 @@ HighlightCell * StorageListController::expressionCells(int index) {
 void StorageListController::willDisplayTitleCellAtIndex(HighlightCell * cell, int j) {
   TextFieldFunctionTitleCell * titleCell = static_cast<TextFieldFunctionTitleCell *>(cell);
   if (!titleCell->isEditing()) {
-    StorageFunction * function = modelStore()->modelForRecord(modelStore()->recordAtIndex(j));
+    ExpiringPointer<StorageFunction> function = modelStore()->modelForRecord(modelStore()->recordAtIndex(j));
     setFunctionNameInTextField(function, titleCell->textField());
     KDColor functionNameColor = function->isActive() ? function->color() : Palette::GreyDark;
     titleCell->setColor(functionNameColor);
@@ -134,12 +134,12 @@ void StorageListController::willDisplayTitleCellAtIndex(HighlightCell * cell, in
 void StorageListController::willDisplayExpressionCellAtIndex(HighlightCell * cell, int j) {
   Shared::StorageFunctionListController::willDisplayExpressionCellAtIndex(cell, j);
   FunctionExpressionCell * myCell = (FunctionExpressionCell *)cell;
-  StorageFunction * f = modelStore()->modelForRecord(modelStore()->recordAtIndex(j));
+  ExpiringPointer<StorageFunction> f = modelStore()->modelForRecord(modelStore()->recordAtIndex(j));
   KDColor textColor = f->isActive() ? KDColorBlack : Palette::GreyDark;
   myCell->setTextColor(textColor);
 }
 
-void StorageListController::setFunctionNameInTextField(StorageFunction * function, TextField * textField) {
+void StorageListController::setFunctionNameInTextField(ExpiringPointer<StorageFunction> function, TextField * textField) {
   char bufferName[BufferTextView::k_maxNumberOfChar];
   function->nameWithArgument(bufferName, BufferTextView::k_maxNumberOfChar, modelStore()->symbol());
   textField->setText(bufferName);
diff --git a/apps/graph/list/storage_list_controller.h b/apps/graph/list/storage_list_controller.h
index 492d211d2..7ae7ef527 100644
--- a/apps/graph/list/storage_list_controller.h
+++ b/apps/graph/list/storage_list_controller.h
@@ -31,7 +31,7 @@ private:
   Shared::TextFieldDelegateApp * textFieldDelegateApp() override {
     return static_cast<Shared::TextFieldDelegateApp *>(app());
   }
-  void setFunctionNameInTextField(Shared::StorageFunction * function, TextField * textField);
+  void setFunctionNameInTextField(Shared::ExpiringPointer<Shared::StorageFunction> function, TextField * textField);
   TextFieldFunctionTitleCell m_functionTitleCells[k_maxNumberOfDisplayableRows];
   Shared::FunctionExpressionCell m_expressionCells[k_maxNumberOfDisplayableRows];
   ListParameterController m_parameterController;
diff --git a/apps/graph/storage_cartesian_function_store.h b/apps/graph/storage_cartesian_function_store.h
index c23a8a129..449b17f9d 100644
--- a/apps/graph/storage_cartesian_function_store.h
+++ b/apps/graph/storage_cartesian_function_store.h
@@ -10,7 +10,7 @@ namespace Graph {
 
 class StorageCartesianFunctionStore : public Shared::StorageFunctionStore {
 public:
-  Shared::StorageCartesianFunction * modelForRecord(Ion::Storage::Record record) const override { return static_cast<Shared::StorageCartesianFunction *>(Shared::StorageFunctionStore::modelForRecord(record)); }
+  Shared::ExpiringPointer<Shared::StorageCartesianFunction> modelForRecord(Ion::Storage::Record record) const { return Shared::ExpiringPointer<Shared::StorageCartesianFunction>(static_cast<Shared::StorageCartesianFunction *>(privateModelForRecord(record))); }
   static char Symbol() { return 'x'; }
   char symbol() const override { return Symbol(); }
 private:
diff --git a/apps/graph/values/storage_function_parameter_controller.cpp b/apps/graph/values/storage_function_parameter_controller.cpp
index 767ab9fbe..667ab51a0 100644
--- a/apps/graph/values/storage_function_parameter_controller.cpp
+++ b/apps/graph/values/storage_function_parameter_controller.cpp
@@ -69,7 +69,7 @@ void StorageFunctionParameterController::willDisplayCellForIndex(HighlightCell *
   }
 }
 
-StorageCartesianFunction * StorageFunctionParameterController::function() {
+ExpiringPointer<StorageCartesianFunction> StorageFunctionParameterController::function() {
   App * a = static_cast<App *>(app());
   return a->functionStore()->modelForRecord(m_record);
 }
diff --git a/apps/graph/values/storage_function_parameter_controller.h b/apps/graph/values/storage_function_parameter_controller.h
index c56e754af..205320927 100644
--- a/apps/graph/values/storage_function_parameter_controller.h
+++ b/apps/graph/values/storage_function_parameter_controller.h
@@ -1,6 +1,7 @@
 #ifndef GRAPH_STORAGE_FUNCTION_PARAM_CONTROLLER_H
 #define GRAPH_STORAGE_FUNCTION_PARAM_CONTROLLER_H
 
+#include "../../shared/expiring_pointer.h"
 #include "../../shared/storage_cartesian_function.h"
 #include "../../shared/storage_values_function_parameter_controller.h"
 
@@ -18,7 +19,7 @@ public:
   void willDisplayCellForIndex(HighlightCell * cell, int index) override;
   void viewWillAppear() override;
 private:
-  Shared::StorageCartesianFunction * function();
+  Shared::ExpiringPointer<Shared::StorageCartesianFunction> function();
 #if COPY_COLUMN
   constexpr static int k_totalNumberOfCell = 2;
 #else
diff --git a/apps/graph/values/storage_values_controller.cpp b/apps/graph/values/storage_values_controller.cpp
index 988d14d10..fe8bcd302 100644
--- a/apps/graph/values/storage_values_controller.cpp
+++ b/apps/graph/values/storage_values_controller.cpp
@@ -41,7 +41,7 @@ void StorageValuesController::willDisplayCellAtLocation(HighlightCell * cell, in
   // The cell is a function title cell:
   if (j == 0 && i > 0) {
     Shared::BufferFunctionTitleCell * myFunctionCell = (Shared::BufferFunctionTitleCell *)cell;
-    Shared::StorageCartesianFunction * function = functionStore()->modelForRecord(recordAtColumn(i));
+    Shared::ExpiringPointer<StorageCartesianFunction> function = functionStore()->modelForRecord(recordAtColumn(i));
     const size_t bufferNameSize = Shared::StorageFunction::k_maxNameWithArgumentSize + 1;
     char bufferName[bufferNameSize];
     if (isDerivativeColumn(i)) {
@@ -70,7 +70,7 @@ Ion::Storage::Record StorageValuesController::recordAtColumn(int i) {
   int index = 1;
   for (int k = 0; k < functionStore()->numberOfDefinedModels(); k++) {
     Ion::Storage::Record record = functionStore()->definedRecordAtIndex(k);
-    StorageCartesianFunction * f = functionStore()->modelForRecord(record);
+    ExpiringPointer<StorageCartesianFunction> f = functionStore()->modelForRecord(record);
     if (f->isActive()) {
       if (i == index) {
         return record;
@@ -92,7 +92,7 @@ bool StorageValuesController::isDerivativeColumn(int i) {
   assert(i >= 1);
   int index = 1;
   for (int k = 0; k < functionStore()->numberOfDefinedModels(); k++) {
-    StorageCartesianFunction * f = functionStore()->modelForRecord(functionStore()->definedRecordAtIndex(k));
+    ExpiringPointer<StorageCartesianFunction> f = functionStore()->modelForRecord(functionStore()->definedRecordAtIndex(k));
     if (f->isActive()) {
       if (i == index) {
         return false;
@@ -139,7 +139,7 @@ StorageFunctionParameterController * StorageValuesController::functionParameterC
 }
 
 double StorageValuesController::evaluationOfAbscissaAtColumn(double abscissa, int columnIndex) {
-  Shared::StorageCartesianFunction * function = functionStore()->modelForRecord(recordAtColumn(columnIndex));
+  Shared::ExpiringPointer<StorageCartesianFunction> function = functionStore()->modelForRecord(recordAtColumn(columnIndex));
   TextFieldDelegateApp * myApp = (TextFieldDelegateApp *)app();
   if (isDerivativeColumn(columnIndex)) {
     return function->approximateDerivative(abscissa, myApp->localContext());
@@ -150,7 +150,7 @@ double StorageValuesController::evaluationOfAbscissaAtColumn(double abscissa, in
 void StorageValuesController::updateNumberOfColumns() {
   int result = 1;
   for (int i = 0; i < functionStore()->numberOfActiveFunctions(); i++) {
-    StorageCartesianFunction * f = functionStore()->modelForRecord(functionStore()->activeRecordAtIndex(i));
+    ExpiringPointer<StorageCartesianFunction> f = functionStore()->modelForRecord(functionStore()->activeRecordAtIndex(i));
     if (f->isActive()) {
       result += 1 + f->displayDerivative();
     }
diff --git a/apps/shared/Makefile b/apps/shared/Makefile
index db1d6dd7f..28f6a1e12 100644
--- a/apps/shared/Makefile
+++ b/apps/shared/Makefile
@@ -9,6 +9,7 @@ app_objs += $(addprefix apps/shared/,\
   curve_view_range.o\
   double_pair_store.o\
   editable_cell_table_view_controller.o\
+  expiring_pointer.o\
   expression_field_delegate_app.o\
   expression_model.o\
   expression_model_list_controller.o\
diff --git a/apps/shared/expiring_pointer.cpp b/apps/shared/expiring_pointer.cpp
new file mode 100644
index 000000000..6f7096e24
--- /dev/null
+++ b/apps/shared/expiring_pointer.cpp
@@ -0,0 +1,17 @@
+#include "expiring_pointer.h"
+#include "storage_expression_model.h"
+#include "storage_cartesian_function.h"
+#include "storage_function.h"
+
+namespace Shared {
+
+#if DEBUG
+template<>
+StorageExpressionModel * ExpiringPointer<StorageExpressionModel>::s_global = nullptr;
+template<>
+StorageFunction * ExpiringPointer<StorageFunction>::s_global = nullptr;
+template<>
+StorageCartesianFunction * ExpiringPointer<StorageCartesianFunction>::s_global = nullptr;
+#endif
+
+}
diff --git a/apps/shared/expiring_pointer.h b/apps/shared/expiring_pointer.h
new file mode 100644
index 000000000..75cdbe5c4
--- /dev/null
+++ b/apps/shared/expiring_pointer.h
@@ -0,0 +1,37 @@
+#ifndef SHARED_EXPIRING_POINTER_H
+#define SHARED_EXPIRING_POINTER_H
+
+#include <escher.h>
+
+namespace Shared {
+
+template <class T>
+class ExpiringPointer {
+public:
+  ExpiringPointer(T * rawPointer, bool reinitGlobal = true) : m_rawPointer(rawPointer) {
+#if DEBUG
+    s_global = rawPointer;
+#endif
+  }
+  T *operator->() {
+#if DEBUG
+    assert(m_rawPointer != nullptr && m_rawPointer == s_global);
+#endif
+    return m_rawPointer;
+  }
+  T &operator*() {
+#if DEBUG
+    assert(m_rawPointer != nullptr && m_rawPointer == s_global);
+#endif
+    return *m_rawPointer;
+  }
+private:
+#if DEBUG
+  static T * s_global;
+#endif
+  T * m_rawPointer;
+};
+
+}
+
+#endif
diff --git a/apps/shared/storage_expression_model_list_controller.cpp b/apps/shared/storage_expression_model_list_controller.cpp
index 24ace6951..36fe8b55c 100644
--- a/apps/shared/storage_expression_model_list_controller.cpp
+++ b/apps/shared/storage_expression_model_list_controller.cpp
@@ -19,7 +19,7 @@ KDCoordinate StorageExpressionModelListController::expressionRowHeight(int j) {
   if (isAddEmptyRow(j)) {
     return Metric::StoreRowHeight;
   }
-  StorageExpressionModel * m = modelStore()->modelForRecord(modelStore()->recordAtIndex(j));
+  ExpiringPointer<StorageExpressionModel> m = modelStore()->modelForRecord(modelStore()->recordAtIndex(j));
   if (m->layout().isUninitialized()) {
     return Metric::StoreRowHeight;
   }
@@ -30,7 +30,7 @@ KDCoordinate StorageExpressionModelListController::expressionRowHeight(int j) {
 
 void StorageExpressionModelListController::willDisplayExpressionCellAtIndex(HighlightCell * cell, int j) {
   EvenOddExpressionCell * myCell = (EvenOddExpressionCell *)cell;
-  StorageExpressionModel * m = modelStore()->modelForRecord(modelStore()->recordAtIndex(j));
+  ExpiringPointer<StorageExpressionModel> m = modelStore()->modelForRecord(modelStore()->recordAtIndex(j));
   myCell->setLayout(m->layout());
 }
 
@@ -50,7 +50,7 @@ bool StorageExpressionModelListController::handleEventOnExpression(Ion::Events::
   }
   if (event == Ion::Events::Backspace && !isAddEmptyRow(selectedRow())) {
     Ion::Storage::Record record = modelStore()->recordAtIndex(modelIndexForRow(selectedRow()));
-    StorageExpressionModel * model =  modelStore()->modelForRecord(record);
+    ExpiringPointer<StorageExpressionModel> model =  modelStore()->modelForRecord(record);
     if (model->shouldBeClearedBeforeRemove()) {
       reinitExpression(model);
     } else {
@@ -81,7 +81,7 @@ void StorageExpressionModelListController::addEmptyModel() {
   editExpression(Ion::Events::OK);
 }
 
-void StorageExpressionModelListController::reinitExpression(StorageExpressionModel * model) {
+void StorageExpressionModelListController::reinitExpression(ExpiringPointer<StorageExpressionModel> model) {
   model->setContent("");
   selectableTableView()->reloadData();
 }
@@ -91,7 +91,7 @@ void StorageExpressionModelListController::editExpression(Ion::Events::Event eve
   char initialTextContent[TextField::maxBufferSize()];
   if (event == Ion::Events::OK || event == Ion::Events::EXE) {
     Ion::Storage::Record record = modelStore()->recordAtIndex(modelIndexForRow(selectedRow()));
-    StorageExpressionModel * model =  modelStore()->modelForRecord(record);
+    ExpiringPointer<StorageExpressionModel> model =  modelStore()->modelForRecord(record);
     model->text(initialTextContent, TextField::maxBufferSize());
     initialText = initialTextContent;
   }
@@ -108,7 +108,7 @@ void StorageExpressionModelListController::editExpression(Ion::Events::Event eve
 
 void StorageExpressionModelListController::editSelectedRecordWithText(const char * text) {
   Ion::Storage::Record record = modelStore()->recordAtIndex(modelIndexForRow(selectedRow()));
-  StorageExpressionModel * model =  modelStore()->modelForRecord(record);
+  ExpiringPointer<StorageExpressionModel> model =  modelStore()->modelForRecord(record);
   model->setContent(text);
 }
 
diff --git a/apps/shared/storage_expression_model_list_controller.h b/apps/shared/storage_expression_model_list_controller.h
index 9e9043b24..5c6eaa806 100644
--- a/apps/shared/storage_expression_model_list_controller.h
+++ b/apps/shared/storage_expression_model_list_controller.h
@@ -20,7 +20,7 @@ protected:
   bool handleEventOnExpression(Ion::Events::Event event);
   virtual void addEmptyModel();
   virtual void didChangeModelsList() {}
-  virtual void reinitExpression(StorageExpressionModel * model);
+  virtual void reinitExpression(ExpiringPointer<StorageExpressionModel> model);
   virtual void editExpression(Ion::Events::Event event);
   virtual void editSelectedRecordWithText(const char * text);
   virtual bool removeModelRow(Ion::Storage::Record record);
diff --git a/apps/shared/storage_expression_model_store.cpp b/apps/shared/storage_expression_model_store.cpp
index 21c9cc867..ab7a75ad0 100644
--- a/apps/shared/storage_expression_model_store.cpp
+++ b/apps/shared/storage_expression_model_store.cpp
@@ -15,7 +15,7 @@ Ion::Storage::Record StorageExpressionModelStore::recordAtIndex(int i) const {
   return Ion::Storage::sharedStorage()->recordWithExtensionAtIndex(modelExtension(), i);
 }
 
-StorageExpressionModel * StorageExpressionModelStore::modelForRecord(Ion::Storage::Record record) const {
+StorageExpressionModel * StorageExpressionModelStore::privateModelForRecord(Ion::Storage::Record record) const {
   uint32_t currentStorageChecksum = Ion::Storage::sharedStorage()->checksum();
   /* If the storage changed since last call to modelForRecord, we invalid all
    * memoized models. Indeed, if f(x) = A+x, and A changed, f(x) memoization
@@ -55,12 +55,12 @@ void StorageExpressionModelStore::tidy() {
 int StorageExpressionModelStore::numberOfModelsSatisfyingTest(ModelTest test) const {
   int result = 0;
   int i = 0;
-  StorageExpressionModel * m = modelForRecord(recordAtIndex(i++));
+  StorageExpressionModel * m = privateModelForRecord(recordAtIndex(i++));
   while (!m->isNull()) {
     if (test(m)) {
       result++;
     }
-    m = modelForRecord(recordAtIndex(i++));
+    m = privateModelForRecord(recordAtIndex(i++));
   }
   return result;
 }
@@ -70,7 +70,7 @@ Ion::Storage::Record StorageExpressionModelStore::recordStatifyingTestAtIndex(in
   int index = 0;
   int currentModelIndex = 0;
   Ion::Storage::Record r = recordAtIndex(currentModelIndex++);
-  StorageExpressionModel * m = modelForRecord(r);
+  StorageExpressionModel * m = privateModelForRecord(r);
   while (!m->isNull()) {
     assert(currentModelIndex <= numberOfModels());
     if (test(m)) {
@@ -80,7 +80,7 @@ Ion::Storage::Record StorageExpressionModelStore::recordStatifyingTestAtIndex(in
       index++;
     }
     r = recordAtIndex(currentModelIndex++);
-    m = modelForRecord(r);
+    m = privateModelForRecord(r);
   }
   assert(false);
   return Ion::Storage::Record();
diff --git a/apps/shared/storage_expression_model_store.h b/apps/shared/storage_expression_model_store.h
index 9d711bc83..0749fbfe0 100644
--- a/apps/shared/storage_expression_model_store.h
+++ b/apps/shared/storage_expression_model_store.h
@@ -2,6 +2,7 @@
 #define SHARED_STORAGE_EXPRESSION_MODEL_STORE_H
 
 #include "storage_expression_model.h"
+#include "expiring_pointer.h"
 #include <ion/storage.h>
 #include <assert.h>
 
@@ -19,7 +20,7 @@ public:
   int numberOfDefinedModels() const { return numberOfModelsSatisfyingTest([](StorageExpressionModel * m) { return m->isDefined(); }); }
   Ion::Storage::Record recordAtIndex(int i) const;
   Ion::Storage::Record definedRecordAtIndex(int i) const { return recordStatifyingTestAtIndex(i, [](StorageExpressionModel * m) { return m->isDefined(); }); }
-  virtual StorageExpressionModel * modelForRecord(Ion::Storage::Record record) const;
+  ExpiringPointer<StorageExpressionModel> modelForRecord(Ion::Storage::Record record) const { return ExpiringPointer<StorageExpressionModel>(privateModelForRecord(record)); }
 
   // Add and Remove
   virtual Ion::Storage::Record::ErrorStatus addEmptyModel() = 0;
@@ -33,6 +34,7 @@ protected:
   typedef bool (*ModelTest)(StorageExpressionModel * model);
   int numberOfModelsSatisfyingTest(ModelTest test) const;
   Ion::Storage::Record recordStatifyingTestAtIndex(int i, ModelTest test) const;
+  StorageExpressionModel * privateModelForRecord(Ion::Storage::Record record) const;
 private:
   void resetMemoizedModels() const;
   virtual void setMemoizedModelAtIndex(int cacheIndex, Ion::Storage::Record) const = 0;
diff --git a/apps/shared/storage_function_banner_delegate.cpp b/apps/shared/storage_function_banner_delegate.cpp
index c38359b7a..a59d2bd07 100644
--- a/apps/shared/storage_function_banner_delegate.cpp
+++ b/apps/shared/storage_function_banner_delegate.cpp
@@ -7,7 +7,7 @@ using namespace Poincare;
 namespace Shared {
 
 void StorageFunctionBannerDelegate::reloadBannerViewForCursorOnFunction(CurveViewCursor * cursor, Ion::Storage::Record record, StorageFunctionStore * functionStore, char symbol) {
-  StorageFunction * function = functionStore->modelForRecord(record);
+  ExpiringPointer<StorageFunction> function = functionStore->modelForRecord(record);
   constexpr int bufferSize = k_maxNumberOfCharacters+PrintFloat::bufferSizeForFloatsWithPrecision(Constant::LargeNumberOfSignificantDigits);
   char buffer[bufferSize];
   const char * space = " ";
diff --git a/apps/shared/storage_function_go_to_parameter_controller.cpp b/apps/shared/storage_function_go_to_parameter_controller.cpp
index 66728f009..622b3ccff 100644
--- a/apps/shared/storage_function_go_to_parameter_controller.cpp
+++ b/apps/shared/storage_function_go_to_parameter_controller.cpp
@@ -23,7 +23,7 @@ double StorageFunctionGoToParameterController::parameterAtIndex(int index) {
 bool StorageFunctionGoToParameterController::setParameterAtIndex(int parameterIndex, double f) {
   assert(parameterIndex == 0);
   StorageFunctionApp * myApp = (StorageFunctionApp *)app();
-  StorageFunction * function = myApp->functionStore()->modelForRecord(m_record);
+  ExpiringPointer<StorageFunction> function = myApp->functionStore()->modelForRecord(m_record);
   float y = function->evaluateAtAbscissa(f, myApp->localContext());
   if (std::fabs(f) > k_maxDisplayableFloat || std::fabs(y) > k_maxDisplayableFloat) {
     app()->displayWarning(I18n::Message::ForbiddenValue);
diff --git a/apps/shared/storage_function_graph_controller.cpp b/apps/shared/storage_function_graph_controller.cpp
index 591149fde..ede44c85e 100644
--- a/apps/shared/storage_function_graph_controller.cpp
+++ b/apps/shared/storage_function_graph_controller.cpp
@@ -89,7 +89,7 @@ InteractiveCurveViewRangeDelegate::Range StorageFunctionGraphController::compute
     return range;
   }
   for (int i=0; i<functionStore()->numberOfActiveFunctions(); i++) {
-    StorageFunction * f = functionStore()->modelForRecord(functionStore()->activeRecordAtIndex(i));
+    ExpiringPointer<StorageFunction> f = functionStore()->modelForRecord(functionStore()->activeRecordAtIndex(i));
     float y = 0.0f;
     float res = curveView()->resolution();
     /* Scan x-range from the middle to the extrema in order to get balanced
@@ -125,7 +125,7 @@ void StorageFunctionGraphController::initCursorParameters() {
   int functionIndex = 0;
   double y = 0;
   do {
-    StorageFunction * firstFunction = functionStore()->modelForRecord(functionStore()->activeRecordAtIndex(functionIndex++));
+    ExpiringPointer<StorageFunction> firstFunction = functionStore()->modelForRecord(functionStore()->activeRecordAtIndex(functionIndex++));
     y = firstFunction->evaluateAtAbscissa(x, myApp->localContext());
   } while ((std::isnan(y) || std::isinf(y)) && functionIndex < functionStore()->numberOfActiveFunctions());
   m_cursor->moveTo(x, y);
diff --git a/apps/shared/storage_function_store.h b/apps/shared/storage_function_store.h
index 34c15d075..acccd4975 100644
--- a/apps/shared/storage_function_store.h
+++ b/apps/shared/storage_function_store.h
@@ -17,7 +17,7 @@ public:
   int numberOfActiveFunctions() const { return numberOfModelsSatisfyingTest([](StorageExpressionModel * m) { return m->isDefined() && static_cast<StorageFunction *>(m)->isActive(); }); }
   Ion::Storage::Record activeRecordAtIndex(int i) const { return recordStatifyingTestAtIndex(i, [](StorageExpressionModel * m) { return m->isDefined() && static_cast<StorageFunction *>(m)->isActive(); }); }
 
-  StorageFunction * modelForRecord(Ion::Storage::Record record) const override { return static_cast<StorageFunction *>(StorageExpressionModelStore::modelForRecord(record)); }
+  ExpiringPointer<StorageFunction> modelForRecord(Ion::Storage::Record record) const { return ExpiringPointer<StorageFunction>(static_cast<StorageFunction *>(privateModelForRecord(record))); }
 
   virtual char symbol() const = 0;
 };
diff --git a/apps/shared/storage_list_parameter_controller.cpp b/apps/shared/storage_list_parameter_controller.cpp
index ea9a03aae..b518db47e 100644
--- a/apps/shared/storage_list_parameter_controller.cpp
+++ b/apps/shared/storage_list_parameter_controller.cpp
@@ -94,7 +94,7 @@ bool StorageListParameterController::handleEnterOnRow(int rowIndex) {
   }
 }
 
-StorageFunction * StorageListParameterController::function() {
+ExpiringPointer<StorageFunction> StorageListParameterController::function() {
   return functionStore()->modelForRecord(m_record);
 }
 
diff --git a/apps/shared/storage_list_parameter_controller.h b/apps/shared/storage_list_parameter_controller.h
index 4003b6670..46aeb8921 100644
--- a/apps/shared/storage_list_parameter_controller.h
+++ b/apps/shared/storage_list_parameter_controller.h
@@ -34,7 +34,7 @@ protected:
   SelectableTableView m_selectableTableView;
   Ion::Storage::Record m_record;
 private:
-  StorageFunction * function();
+  ExpiringPointer<StorageFunction> function();
   StorageFunctionStore * functionStore();
 #if FUNCTION_COLOR_CHOICE
   MessageTableCellWithChevron m_colorCell;
diff --git a/apps/shared/storage_sum_graph_controller.cpp b/apps/shared/storage_sum_graph_controller.cpp
index 4b41aae33..6d2997718 100644
--- a/apps/shared/storage_sum_graph_controller.cpp
+++ b/apps/shared/storage_sum_graph_controller.cpp
@@ -103,7 +103,7 @@ bool StorageSumGraphController::handleEvent(Ion::Events::Event event) {
 bool StorageSumGraphController::moveCursorHorizontallyToPosition(double x) {
   StorageFunctionApp * myApp = static_cast<StorageFunctionApp *>(app());
   assert(!m_record.isNull());
-  StorageFunction * function = myApp->functionStore()->modelForRecord(m_record);
+  ExpiringPointer<StorageFunction> function = myApp->functionStore()->modelForRecord(m_record);
   double y = function->evaluateAtAbscissa(x, myApp->localContext());
   m_cursor->moveTo(x, y);
   if (m_step == Step::FirstParameter) {
@@ -191,7 +191,7 @@ bool StorageSumGraphController::handleEnter() {
   m_step = (Step)((int)m_step+1);
   StorageFunctionApp * myApp = static_cast<StorageFunctionApp *>(app());
   assert(!m_record.isNull());
-  StorageFunction * function = myApp->functionStore()->modelForRecord(m_record);
+  ExpiringPointer<StorageFunction> function = myApp->functionStore()->modelForRecord(m_record);
   double sum = function->sumBetweenBounds(m_startSum, m_endSum, myApp->localContext());
   m_legendView.setSumSymbol(m_step, m_startSum, m_endSum, sum, createFunctionLayout(function));
   m_legendView.setLegendMessage(I18n::Message::Default, m_step);
diff --git a/apps/shared/storage_sum_graph_controller.h b/apps/shared/storage_sum_graph_controller.h
index 85fece226..0f5189133 100644
--- a/apps/shared/storage_sum_graph_controller.h
+++ b/apps/shared/storage_sum_graph_controller.h
@@ -9,6 +9,7 @@
 #include "simple_interactive_curve_view_controller.h"
 #include "storage_function.h"
 #include "text_field_delegate.h"
+#include "expiring_pointer.h"
 
 namespace Shared {
 
@@ -39,7 +40,7 @@ private:
   constexpr static float k_cursorBottomMarginRatio = 0.28f; // (cursorHeight/2+bannerHeigh)/graphViewHeight
   virtual I18n::Message legendMessageAtStep(Step step) = 0;
   virtual double cursorNextStep(double position, int direction) = 0;
-  virtual Poincare::Layout createFunctionLayout(StorageFunction * function) = 0;
+  virtual Poincare::Layout createFunctionLayout(ExpiringPointer<StorageFunction> function) = 0;
   Shared::InteractiveCurveViewRange * interactiveCurveViewRange() override { return m_graphRange; }
   Shared::CurveView * curveView() override { return m_graphView; }
   TextFieldDelegateApp * textFieldDelegateApp() override {
diff --git a/apps/shared/storage_values_controller.cpp b/apps/shared/storage_values_controller.cpp
index 38d14a041..99f4606dc 100644
--- a/apps/shared/storage_values_controller.cpp
+++ b/apps/shared/storage_values_controller.cpp
@@ -309,7 +309,7 @@ int StorageValuesController::maxNumberOfElements() const {
 }
 
 double StorageValuesController::evaluationOfAbscissaAtColumn(double abscissa, int columnIndex) {
-  StorageFunction * function = functionStore()->modelForRecord(recordAtColumn(columnIndex));
+  ExpiringPointer<StorageFunction> function = functionStore()->modelForRecord(recordAtColumn(columnIndex));
   TextFieldDelegateApp * myApp = (TextFieldDelegateApp *)app();
   return function->evaluateAtAbscissa(abscissa, myApp->localContext());
 }