diff --git a/newsfragments/556.misc b/newsfragments/556.misc
new file mode 100644
index 000000000..afbc18dd9
--- /dev/null
+++ b/newsfragments/556.misc
@@ -0,0 +1 @@
+Correct some tests following changes to the definition of ``trusted_range``.
diff --git a/tests/format/test_FormatNXmxDLS.py b/tests/format/test_FormatNXmxDLS.py
index 24ced8c61..ea7e91b6f 100644
--- a/tests/format/test_FormatNXmxDLS.py
+++ b/tests/format/test_FormatNXmxDLS.py
@@ -34,7 +34,7 @@ def test_VMXi_rotation_scan():
     assert (
         tuple(reversed(panel.get_image_size())) == imageset[0][0].all() == (2162, 2068)
     )
-    assert panel.get_trusted_range() == (-1, 23315)
+    assert panel.get_trusted_range() == (0, 23315)
     assert panel.get_fast_axis() == (1, 0, 0)
     assert panel.get_slow_axis() == (0, -1, 0)
     assert panel.get_origin() == pytest.approx((-79.155, 87.4875, -183.1849844439))
diff --git a/tests/format/test_FormatNXmxDLS16M.py b/tests/format/test_FormatNXmxDLS16M.py
index 5006c1dce..f39749566 100644
--- a/tests/format/test_FormatNXmxDLS16M.py
+++ b/tests/format/test_FormatNXmxDLS16M.py
@@ -45,7 +45,7 @@ def test_rotation_scan_i04(master_h5):
     panel = detector[0]
     assert panel.get_pixel_size() == (0.075, 0.075)
     assert panel.get_image_size() == (4148, 4362)
-    assert panel.get_trusted_range() == (-1, 22726)
+    assert panel.get_trusted_range() == (0, 22726)
     assert panel.get_fast_axis() == (1, 0, 0)
     assert panel.get_slow_axis() == (0, -1, 0)
     assert panel.get_origin() == pytest.approx(
@@ -159,7 +159,7 @@ def test_grid_scan_i04():
     panel = detector[0]
     assert panel.get_pixel_size() == (0.075, 0.075)
     assert panel.get_image_size() == (4148, 4362)
-    assert panel.get_trusted_range() == (-1, 65535)
+    assert panel.get_trusted_range() == (0, 65535)
     assert panel.get_fast_axis() == (1, 0, 0)
     assert panel.get_slow_axis() == (0, -1, 0)
     assert panel.get_origin() == pytest.approx(