diff --git a/scico/test/flax/test_inv.py b/scico/test/flax/test_inv.py
index f13db77f..ee2f04d5 100644
--- a/scico/test/flax/test_inv.py
+++ b/scico/test/flax/test_inv.py
@@ -159,7 +159,6 @@ def setup_method(self, method):
         self.opCT = XRayTransform2D(
             input_shape=(self.N, self.N),
             det_count=self.N,
-            det_spacing=1.0,
             angles=angles,
         )  # Radon transform operator
         a_f = lambda v: jnp.atleast_3d(self.opCT(v.squeeze()))