diff --git a/python/spline2D_eikonal.py b/python/spline2D_eikonal.py
index d3852d2a196179c72fb1dd56d9e9dd5ae4b90e8c..dd4874efc2d38c5e35bdc9e8aca096607fe9269e 100644
--- a/python/spline2D_eikonal.py
+++ b/python/spline2D_eikonal.py
@@ -69,7 +69,7 @@ def computePsiList(Tmat, param):
             p1 = np.linspace(0, param.nbFct - 1, param.nbFct)
             p2 = np.linspace(0, param.nbFct - 2, param.nbFct - 1)
             T[d, :] = tt**p1
-            dT[d, 1:] = p1[1:] @ tt**p2 * param.nbSeg
+            dT[d, 1:] = p1[1:] * tt**p2 * param.nbSeg
             idl[:, d] = id.astype("int") * param.nbFct + p1
 
         # Reconstruct Psi for all dimensions