diff --git a/apps/regression/model/model.cpp b/apps/regression/model/model.cpp
index 2d223ec7e..8aec7709a 100644
--- a/apps/regression/model/model.cpp
+++ b/apps/regression/model/model.cpp
@@ -35,6 +35,7 @@ void Model::fit(Store * store, int series, double * modelCoefficients, Poincare:
   if (dataSuitableForFit(store, series)) {
     initCoefficientsForFit(modelCoefficients, k_initialCoefficientValue, false, store, series);
     fitLevenbergMarquardt(store, series, modelCoefficients, context);
+    uniformizeCoefficientsFromFit(modelCoefficients);
   } else {
     initCoefficientsForFit(modelCoefficients, NAN, true);
   }
diff --git a/apps/regression/model/model.h b/apps/regression/model/model.h
index 78f14aab6..1b36fa6a8 100644
--- a/apps/regression/model/model.h
+++ b/apps/regression/model/model.h
@@ -64,6 +64,7 @@ private:
   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;
+  virtual void uniformizeCoefficientsFromFit(double * modelCoefficients) const {}
 };
 
 }
diff --git a/apps/regression/model/trigonometric_model.cpp b/apps/regression/model/trigonometric_model.cpp
index aba971665..b8338964e 100644
--- a/apps/regression/model/trigonometric_model.cpp
+++ b/apps/regression/model/trigonometric_model.cpp
@@ -104,6 +104,29 @@ void TrigonometricModel::specializedInitCoefficientsForFit(double * modelCoeffic
   modelCoefficients[2] = 0.0;
 }
 
+void TrigonometricModel::uniformizeCoefficientsFromFit(double * modelCoefficients) const {
+  // Coefficients must be unique.
+  double piInAngleUnit = M_PI / toRadians(Poincare::Preferences::sharedPreferences()->angleUnit());
+  // A must be positive.
+  if (modelCoefficients[0] < 0) {
+    // A * sin(B * x + C) + D = -A * sin(B * x + C + π) + D
+    modelCoefficients[0] *= -1;
+    modelCoefficients[2] += piInAngleUnit;
+  }
+  // B must be positive.
+  if (modelCoefficients[1] < 0) {
+    // A * sin(B * x + C) + D = -A * sin(-B * x - C) + D
+    // -A * sin(-B * x - C) + D = A * sin(-B * x - C + π) + D
+    modelCoefficients[1] *= -1;
+    modelCoefficients[2] *= -1;
+    modelCoefficients[2] += piInAngleUnit;
+  }
+  // C must be between -π and π.
+  // A * sin(B * x + C) + D = A * sin(B * x + C - 2π) = A * sin(B * x + C + 2π)
+  // Using remainder(C,2π) = C - 2π * round(C / 2π)
+  modelCoefficients[2] -= 2 * piInAngleUnit * round(modelCoefficients[2] / (2 * piInAngleUnit));
+}
+
 Expression TrigonometricModel::expression(double * modelCoefficients) {
   double a = modelCoefficients[0];
   double b = modelCoefficients[1];
diff --git a/apps/regression/model/trigonometric_model.h b/apps/regression/model/trigonometric_model.h
index 83ed05113..124a6353c 100644
--- a/apps/regression/model/trigonometric_model.h
+++ b/apps/regression/model/trigonometric_model.h
@@ -17,6 +17,7 @@ public:
 private:
   static constexpr int k_numberOfCoefficients = 4;
   void specializedInitCoefficientsForFit(double * modelCoefficients, double defaultValue, Store * store, int series) const override;
+  void uniformizeCoefficientsFromFit(double * modelCoefficients) const override;
   Poincare::Expression expression(double * modelCoefficients) override;
 };