diff --git a/wafo/numba_misc.py b/wafo/numba_misc.py
index 81a3c69..8c5f2d0 100644
--- a/wafo/numba_misc.py
+++ b/wafo/numba_misc.py
@@ -8,7 +8,7 @@ from numba import guvectorize, jit, float64, int64, int32, int8, void
 import numpy as np
 
 
-@guvectorize([(int64[:], int8[:], int64[:])], '(n),(n)->(3)')
+@guvectorize(['void(int64[:], int8[:], int64[:])'], '(n),(n)->(3)')
 def _find_first_cross(ind, y, out):
     ix, dcross, start, v = 0, 0, 0, 0
     n = len(y)