diff --git a/tests/eko/evolution_operator/test_ome.py b/tests/eko/evolution_operator/test_ome.py
index 23ab65e9f..13ab4e13d 100644
--- a/tests/eko/evolution_operator/test_ome.py
+++ b/tests/eko/evolution_operator/test_ome.py
@@ -14,6 +14,7 @@
 )
 from eko.io.runcards import OperatorCard, TheoryCard
 from eko.io.types import InversionMethod
+from eko.matchings import Segment
 from eko.runner import legacy
 from ekore.operator_matrix_elements.unpolarized.space_like import (
     A_non_singlet,
@@ -333,19 +334,19 @@ def test_quad_ker(monkeypatch):
 
 class TestOperatorMatrixElement:
     def test_labels(self, theory_ffns, operator_card, tmp_path: pathlib.Path):
+        theory_card = theory_ffns(3)
         path = tmp_path / "eko.tar"
         for skip_singlet in [True, False]:
             for skip_ns in [True, False]:
                 operator_card.debug.skip_singlet = skip_singlet
                 operator_card.debug.skip_non_singlet = skip_ns
                 path.unlink(missing_ok=True)
-                g = legacy.Runner(theory_ffns(3), operator_card, path=path).op_grid
+                g = legacy.Runner(theory_card, operator_card, path=path).op_grid
                 o = OperatorMatrixElement(
                     g.config,
                     g.managers,
                     is_backward=True,
-                    q2=None,
-                    nf=None,
+                    segment=Segment(theory_card.heavy.masses.b.value**2, None, 4),
                     L=None,
                     is_msbar=False,
                 )
@@ -387,8 +388,7 @@ def test_compute_n3lo(self, theory_ffns, operator_card, tmp_path):
             g.config,
             g.managers,
             is_backward=True,
-            q2=theory_card.heavy.masses.b.value**2,
-            nf=4,
+            segment=Segment(theory_card.heavy.masses.b.value**2, None, 4),
             L=0,
             is_msbar=False,
         )
@@ -419,8 +419,7 @@ def test_compute_lo(self, theory_ffns, operator_card, tmp_path):
             g.config,
             g.managers,
             is_backward=False,
-            q2=theory_card.heavy.masses.b.value**2,
-            nf=4,
+            segment=Segment(theory_card.heavy.masses.b.value**2, None, 4),
             L=0,
             is_msbar=False,
         )
@@ -471,8 +470,7 @@ def test_compute_nlo(self, theory_ffns, operator_card: OperatorCard, tmp_path):
             g.config,
             g.managers,
             is_backward=False,
-            q2=theory_card.heavy.masses.b.value**2,
-            nf=4,
+            segment=Segment(theory_card.heavy.masses.b.value**2, None, 4),
             L=0,
             is_msbar=False,
         )