diff --git a/MathLib/InterpolationAlgorithms/PiecewiseLinearInterpolation.cpp b/MathLib/InterpolationAlgorithms/PiecewiseLinearInterpolation.cpp
index 9973b9470de9122d5a575e0d92276c56e7306318..eb9d8631b4a1aca61b06e61ec9b559cb5b4e691f 100644
--- a/MathLib/InterpolationAlgorithms/PiecewiseLinearInterpolation.cpp
+++ b/MathLib/InterpolationAlgorithms/PiecewiseLinearInterpolation.cpp
@@ -70,7 +70,7 @@ double PiecewiseLinearInterpolation::getValue(double pnt_to_interpolate) const
 	}
 
 	// compute linear interpolation polynom: y = m * (x - support[i]) + value[i]
-	const long double m((_values_at_supp_pnts[interval_idx + 1] - _values_at_supp_pnts[interval_idx])
+	const double m((_values_at_supp_pnts[interval_idx + 1] - _values_at_supp_pnts[interval_idx])
 					/ (_supp_pnts[interval_idx + 1] - _supp_pnts[interval_idx]));
 
 	return m * (pnt_to_interpolate - _supp_pnts[interval_idx]) + _values_at_supp_pnts[interval_idx];