diff --git a/meanas/test/test_fdfd.py b/meanas/test/test_fdfd.py
index 2f7e142..e2e8e7b 100644
--- a/meanas/test/test_fdfd.py
+++ b/meanas/test/test_fdfd.py
@@ -43,8 +43,12 @@ def test_poynting_planes(sim: 'FDResult') -> None:
               s[1, mask].sum(), -s[1, my].sum(),
               s[2, mask].sum(), -s[2, mz].sum()]
 
-    e_dot_j = sim.e * sim.j * sim.dxes[0][0][:, None, None] * sim.dxes[0][1][None, :, None] * sim.dxes[0][2][None, None, :]
-    src_energy = -e_dot_j[:, mask].real / 2
+    e_dot_j = sim.e * sim.j.conj()
+    dv = (sim.dxes[0][0][:, None, None]
+        * sim.dxes[0][1][None, :, None]
+        * sim.dxes[0][2][None, None, :]
+        )
+    src_energy = -(e_dot_j.real * dv)[:, mask] / 2
 
     assert_close(sum(planes), src_energy.sum())