diff --git a/fdfd_tools/bloch.py b/fdfd_tools/bloch.py
index fd5f758..aabc96c 100644
--- a/fdfd_tools/bloch.py
+++ b/fdfd_tools/bloch.py
@@ -352,8 +352,8 @@ def inverse_maxwell_operator_approx(k0: numpy.ndarray,
         d_xyz = fftn(ifftn(e_xyz, axes=range(3)) * epsilon, axes=range(3))
 
         # cross product and transform into mn basis   crossinv_t2c
-        h_m = numpy.sum(e_xyz * n, axis=3)[:, :, :, None] / +k_mag
-        h_n = numpy.sum(e_xyz * m, axis=3)[:, :, :, None] / -k_mag
+        h_m = numpy.sum(d_xyz * n, axis=3)[:, :, :, None] / +k_mag
+        h_n = numpy.sum(d_xyz * m, axis=3)[:, :, :, None] / -k_mag
 
         return numpy.hstack((h_m.ravel(), h_n.ravel()))