diff --git a/apps/regression/model/model.cpp b/apps/regression/model/model.cpp
index bcbb14b19..13f711574 100644
--- a/apps/regression/model/model.cpp
+++ b/apps/regression/model/model.cpp
@@ -40,14 +40,6 @@ void Model::fit(Store * store, int series, double * modelCoefficients, Poincare:
   }
 }
 
-void Model::initCoefficientsForFit(double * modelCoefficients, double defaultValue, bool forceDefaultValue, Store * store, int series) const {
-  assert(defaultValue || (store != nullptr && series >= 0 && series < Store::k_numberOfSeries && !store->seriesIsEmpty(series)));
-  int nbCoef = numberOfCoefficients();
-  for (int i = 0; i < nbCoef; i++) {
-    modelCoefficients[i] = defaultValue;
-  }
-}
-
 bool Model::dataSuitableForFit(Store * store, int series) const {
   if (!store->seriesNumberOfAbscissaeGreaterOrEqualTo(series, numberOfCoefficients())) {
     return false;
@@ -209,5 +201,20 @@ int Model::solveLinearSystem(double * solutions, double * coefficients, double *
   return 0;
 }
 
+void Model::initCoefficientsForFit(double * modelCoefficients, double defaultValue, bool forceDefaultValue, Store * store, int series) const {
+  assert(forceDefaultValue || (store != nullptr && series >= 0 && series < Store::k_numberOfSeries && !store->seriesIsEmpty(series)));
+  if (forceDefaultValue) {
+    Model::specializedInitCoefficientsForFit(modelCoefficients, defaultValue);
+  } else {
+    specializedInitCoefficientsForFit(modelCoefficients, defaultValue, store, series);
+  }
 }
 
+void Model::specializedInitCoefficientsForFit(double * modelCoefficients, double defaultValue, Store * store, int series) const {
+  const int nbCoef = numberOfCoefficients();
+  for (int i = 0; i < nbCoef; i++) {
+    modelCoefficients[i] = defaultValue;
+  }
+}
+
+}
diff --git a/apps/regression/model/model.h b/apps/regression/model/model.h
index 4c2550946..c018a3528 100644
--- a/apps/regression/model/model.h
+++ b/apps/regression/model/model.h
@@ -39,7 +39,6 @@ public:
   virtual int bannerLinesCount() const { return 2; }
 protected:
   // Fit
-  virtual void initCoefficientsForFit(double * modelCoefficients, double defaultValue, bool forceDefaultValue, Store * store = nullptr, int series = -1) const;
   virtual bool dataSuitableForFit(Store * store, int series) const;
   constexpr static const KDFont * k_layoutFont = KDFont::SmallFont;
   Poincare::Layout m_layout;
@@ -62,6 +61,8 @@ private:
   double alphaCoefficient(Store * store, int series, double * modelCoefficients, int k, int l) const;
   double betaCoefficient(Store * store, int series, double * modelCoefficients, int k) const;
   int solveLinearSystem(double * solutions, double * coefficients, double * constants, int solutionDimension, Poincare::Context * context);
+  void initCoefficientsForFit(double * modelCoefficients, double defaultValue, bool forceDefaultValue, Store * store = nullptr, int series = -1) const;
+  virtual void specializedInitCoefficientsForFit(double * modelCoefficients, double defaultValue, Store * store = nullptr, int series = -1) const;
 };
 
 }
diff --git a/apps/regression/model/trigonometric_model.cpp b/apps/regression/model/trigonometric_model.cpp
index b65110481..f32f2c66b 100644
--- a/apps/regression/model/trigonometric_model.cpp
+++ b/apps/regression/model/trigonometric_model.cpp
@@ -70,11 +70,7 @@ double TrigonometricModel::partialDerivate(double * modelCoefficients, int deriv
   return 0.0;
 }
 
-void TrigonometricModel::initCoefficientsForFit(double * modelCoefficients, double defaultValue, bool forceDefaultValue, Store * store, int series) const {
-  if (forceDefaultValue) {
-    Model::initCoefficientsForFit(modelCoefficients, defaultValue, forceDefaultValue);
-    return;
-  }
+void TrigonometricModel::specializedInitCoefficientsForFit(double * modelCoefficients, double defaultValue, Store * store, int series) const {
   assert(store != nullptr && series >= 0 && series < Store::k_numberOfSeries && !store->seriesIsEmpty(series));
   for (int i = 1; i < k_numberOfCoefficients - 1; i++) {
     modelCoefficients[i] = defaultValue;
diff --git a/apps/regression/model/trigonometric_model.h b/apps/regression/model/trigonometric_model.h
index c3fdad8f0..83ed05113 100644
--- a/apps/regression/model/trigonometric_model.h
+++ b/apps/regression/model/trigonometric_model.h
@@ -16,7 +16,7 @@ public:
   int bannerLinesCount() const override { return 4; }
 private:
   static constexpr int k_numberOfCoefficients = 4;
-  void initCoefficientsForFit(double * modelCoefficients, double defaultValue, bool forceDefaultValue, Store * store = nullptr, int series = -1) const override;
+  void specializedInitCoefficientsForFit(double * modelCoefficients, double defaultValue, Store * store, int series) const override;
   Poincare::Expression expression(double * modelCoefficients) override;
 };