diff --git a/apps/regression/app.cpp b/apps/regression/app.cpp
index de483ded2..9331fdefc 100644
--- a/apps/regression/app.cpp
+++ b/apps/regression/app.cpp
@@ -27,7 +27,6 @@ App::Snapshot::Snapshot() :
   m_rangeVersion(0),
   m_selectedSeriesIndex(-1)
 {
-  assert(m_previousModelsVersions[0] == 0);
 }
 
 App * App::Snapshot::unpack(Container * container) {
@@ -35,10 +34,8 @@ App * App::Snapshot::unpack(Container * container) {
 }
 
 void App::Snapshot::reset() {
-  m_store.deleteAllPairs();
+  m_store.reset();
   m_modelVersion = 0;
-  assert(sizeof(m_previousModelsVersions) == sizeof(uint32_t) * GraphController::sNumberOfMemoizedModelVersions);
-  memset(m_previousModelsVersions, 0, sizeof(m_previousModelsVersions));
   m_rangeVersion = 0;
   setActiveTab(0);
 }
diff --git a/apps/regression/app.h b/apps/regression/app.h
index f697d4a49..2c529af77 100644
--- a/apps/regression/app.h
+++ b/apps/regression/app.h
@@ -30,7 +30,7 @@ public:
     int * graphSelectedDotIndex() { return &m_graphSelectedDotIndex; }
     int * selectedSeriesIndex() { return &m_selectedSeriesIndex; }
     uint32_t * modelVersion() { return &m_modelVersion; }
-    uint32_t * previousModelsVersions() { return m_previousModelsVersions; }
+    uint32_t * previousModelsVersions() { return m_store.seriesChecksum(); }
     uint32_t * rangeVersion() { return &m_rangeVersion; }
   private:
     void tidy() override;
@@ -38,7 +38,6 @@ public:
     Shared::CurveViewCursor m_cursor;
     int m_graphSelectedDotIndex;
     uint32_t m_modelVersion;
-    uint32_t m_previousModelsVersions[GraphController::sNumberOfMemoizedModelVersions];
     uint32_t m_rangeVersion;
     int m_selectedSeriesIndex;
   };
diff --git a/apps/regression/graph_controller.cpp b/apps/regression/graph_controller.cpp
index afa38abfe..b6b54aaf1 100644
--- a/apps/regression/graph_controller.cpp
+++ b/apps/regression/graph_controller.cpp
@@ -352,7 +352,8 @@ uint32_t GraphController::modelVersion() {
 }
 
 uint32_t GraphController::modelVersionAtIndex(size_t i) {
-  return m_store->seriesChecksumAtIndex(i);
+  assert(i < numberOfMemoizedVersions());
+  return *(m_store->seriesChecksum() + i);
 }
 
 uint32_t GraphController::rangeVersion() {
diff --git a/apps/regression/graph_controller.h b/apps/regression/graph_controller.h
index 6d434f500..30e722552 100644
--- a/apps/regression/graph_controller.h
+++ b/apps/regression/graph_controller.h
@@ -16,7 +16,6 @@ namespace Regression {
 class GraphController : public Shared::InteractiveCurveViewController {
 
 public:
-  static constexpr size_t sNumberOfMemoizedModelVersions = Store::k_numberOfSeries;
   GraphController(Responder * parentResponder, InputEventHandlerDelegate * inputEventHandlerDelegate, ButtonRowController * header, Store * store, Shared::CurveViewCursor * cursor, uint32_t * modelVersion, uint32_t * previousModelsVersions, uint32_t * rangeVersion, int * selectedDotIndex, int * selectedSeriesIndex);
   ViewController * initialisationParameterController() override;
   bool isEmpty() const override;
@@ -46,7 +45,7 @@ private:
   uint32_t modelVersion() override;
   uint32_t modelVersionAtIndex(size_t i) override;
   uint32_t rangeVersion() override;
-  size_t numberOfMemoizedVersions() const override { return sNumberOfMemoizedModelVersions; }
+  size_t numberOfMemoizedVersions() const override { return Store::k_numberOfSeries; }
   int selectedCurveIndex() const override { return *m_selectedSeriesIndex; }
   bool closestCurveIndexIsSuitable(int newIndex, int currentIndex) const override;
   Poincare::Coordinate2D<double> xyValues(int curveIndex, double x, Poincare::Context * context) const override;
diff --git a/apps/regression/store.cpp b/apps/regression/store.cpp
index 0afd7941a..98f703bd5 100644
--- a/apps/regression/store.cpp
+++ b/apps/regression/store.cpp
@@ -19,13 +19,14 @@ static_assert(Store::k_numberOfSeries == 3, "Number of series changed, Regressio
 Store::Store() :
   InteractiveCurveViewRange(),
   DoublePairStore(),
-  m_seriesChecksum{0, 0, 0},
   m_angleUnit(Poincare::Preferences::AngleUnit::Degree)
 {
-  for (int i = 0; i < k_numberOfSeries; i++) {
-    m_regressionTypes[i] = Model::Type::Linear;
-    m_regressionChanged[i] = false;
-  }
+  resetMemoization();
+}
+
+void Store::reset() {
+  deleteAllPairs();
+  resetMemoization();
 }
 
 void Store::tidy() {
@@ -188,6 +189,13 @@ double Store::doubleCastedNumberOfPairsOfSeries(int series) const {
   return DoublePairStore::numberOfPairsOfSeries(series);
 }
 
+void Store::resetMemoization() {
+  assert(((int)Model::Type::Linear) == 0);
+  memset(m_seriesChecksum, 0, sizeof(m_seriesChecksum));
+  memset(m_regressionTypes, 0, sizeof(m_regressionTypes));
+  memset(m_regressionChanged, 0, sizeof(m_regressionChanged));
+}
+
 float Store::maxValueOfColumn(int series, int i) const {
   float maxColumn = -FLT_MAX;
   for (int k = 0; k < numberOfPairsOfSeries(series); k++) {
diff --git a/apps/regression/store.h b/apps/regression/store.h
index 757ed2b95..2cc6f600f 100644
--- a/apps/regression/store.h
+++ b/apps/regression/store.h
@@ -22,6 +22,7 @@ class Store : public Shared::InteractiveCurveViewRange, public Shared::DoublePai
 public:
   Store();
 
+  void reset();
   // Clean pool
   void tidy();
 
@@ -35,10 +36,7 @@ public:
     assert((int)m_regressionTypes[series] >= 0 && (int)m_regressionTypes[series] < Model::k_numberOfModels);
     return regressionModel((int)m_regressionTypes[series]);
   }
-  uint32_t seriesChecksumAtIndex(size_t i) {
-    assert(i < k_numberOfSeries);
-    return m_seriesChecksum[i];
-  }
+  uint32_t * seriesChecksum() { return m_seriesChecksum; }
 
   // Dots
   /* Return the closest dot to abscissa x above the regression curve if
@@ -74,6 +72,7 @@ public:
   double squaredCorrelationCoefficient(int series) const;
 private:
   constexpr static float k_displayHorizontalMarginRatio = 0.05f;
+  void resetMemoization();
   float maxValueOfColumn(int series, int i) const; //TODO LEA why float ?
   float minValueOfColumn(int series, int i) const; //TODO LEA why float ?
   Model * regressionModel(int index);