diff --git a/NumLib/Fem/ShapeFunction/ShapePyra13-impl.h b/NumLib/Fem/ShapeFunction/ShapePyra13-impl.h
index ab16f593d981de29542d6457030411fe7c7f5c26..ac263ee2d324b65da4b8090483f9b1e336f6a46d 100644
--- a/NumLib/Fem/ShapeFunction/ShapePyra13-impl.h
+++ b/NumLib/Fem/ShapeFunction/ShapePyra13-impl.h
@@ -49,9 +49,9 @@ void ShapePyra13::computeGradShapeFunction(const T_X &x, T_N &dN)
     dN[7] = -0.25 * r * (1.0 + s) * (1.0 - t) * (2.0 - s - s * t);
     dN[8] = -0.125 * (1.0 - s * s) * (1.0 - t) * (1.0 + 2.0 * r - t + 2 * r * t);
     dN[9] = -0.25 * (1.0 - s) * (1.0 - t * t);
-    dN[10] = -dN[9];
+    dN[10] = 0.25 * (1.0 - s) * (1.0 - t * t);
     dN[11] = 0.25 * (1.0 + s) * (1.0 - t * t);
-    dN[12] = -dN[11];
+    dN[12] = -0.25 * (1.0 + s) * (1.0 - t * t);
 
     //---dN/ds
     dN[13] = 0.0625 * (1.0 - r) * (1.0 - t) * (1.0 + r + 6.0 * s + 4.0 * r * s + t - r * t + 2.0 * s * t + 4.0 * r * s * t);
@@ -65,8 +65,8 @@ void ShapePyra13::computeGradShapeFunction(const T_X &x, T_N &dN)
     dN[21] = -0.25 * (1.0 - r) * s * (1.0 - t) * (2.0 + r + r * t);
     dN[22] = -0.25 * (1.0 - r) * (1.0 - t * t);
     dN[23] = -0.25 * (1.0 + r) * (1.0 - t * t);
-    dN[24] = -dN[23];
-    dN[25] = -dN[22];
+    dN[24] = 0.25 * (1.0 + r) * (1.0 - t * t);
+     dN[25] = 0.25 * (1.0 - r) * (1.0 - t * t);
 
     //---dN/dt
     dN[26] = 0.125 * (1.0 - r) * (1.0 - s) * (1.0 + r + s + 2.0 * t + r * t + s * t + 2.0 * r * s * t);