diff --git a/jaxpm/kernels.py b/jaxpm/kernels.py
index 8447f8a..9a0f783 100644
--- a/jaxpm/kernels.py
+++ b/jaxpm/kernels.py
@@ -2,24 +2,6 @@ import jax.numpy as jnp
 import numpy as np
 
 
-def fftk(shape, symmetric=True, finite=False, dtype=np.float32):
-    """ Return k_vector given a shape (nc, nc, nc) and box_size
-  """
-    k = []
-    for d in range(len(shape)):
-        kd = np.fft.fftfreq(shape[d])
-        kd *= 2 * np.pi
-        kdshape = np.ones(len(shape), dtype='int')
-        if symmetric and d == len(shape) - 1:
-            kd = kd[:shape[d] // 2 + 1]
-        kdshape[d] = len(kd)
-        kd = kd.reshape(kdshape)
-
-        k.append(kd.astype(dtype))
-    del kd, kdshape
-    return k
-
-
 def gradient_kernel(kvec, direction, order=1):
     """
   Computes the gradient kernel in the requested direction