diff --git a/src/ekobox/genpdf/__init__.py b/src/ekobox/genpdf/__init__.py
index 5df318de3..5456613d4 100644
--- a/src/ekobox/genpdf/__init__.py
+++ b/src/ekobox/genpdf/__init__.py
@@ -220,10 +220,11 @@ def generate_block(
     xfxQ2: Callable, xgrid: List[float], evolgrid: List[EPoint], pids: List[int]
 ) -> dict:
     """Generate an LHAPDF data block from a callable."""
-    block: dict = dict(mu2grid=[mu2 for mu2, _ in evolgrid], pids=pids, xgrid=xgrid)
+    sorted_q2grid = [float(q2) for q2, _ in np.sort(evolgrid, axis=0)]
+    block: dict = dict(mu2grid=sorted_q2grid, pids=pids, xgrid=xgrid)
     data = []
     for x in xgrid:
-        for mu2, _ in evolgrid:
+        for mu2 in sorted_q2grid:
             data.append(np.array([xfxQ2(pid, x, mu2) for pid in pids]))
     block["data"] = np.array(data)
     return block
diff --git a/tests/ekobox/test_genpdf.py b/tests/ekobox/test_genpdf.py
index 0565db701..fb75fd542 100644
--- a/tests/ekobox/test_genpdf.py
+++ b/tests/ekobox/test_genpdf.py
@@ -44,6 +44,7 @@ def test_generate_block():
     assert sorted(b.keys()) == sorted(["data", "mu2grid", "xgrid", "pids"])
     assert isinstance(b["data"], np.ndarray)
     assert b["data"].shape == (len(xg) * len(mu2s), len(pids))
+    assert b["mu2grid"] == sorted(b["mu2grid"])
 
 
 def test_install_pdf(fake_lhapdf, cd):