diff --git a/.ruff.toml b/.ruff.toml
index f6d0285ea..1979526df 100644
--- a/.ruff.toml
+++ b/.ruff.toml
@@ -77,5 +77,5 @@ required-imports = [
     "from __future__ import annotations",
 ]
 
-[flake8-import-conventions]
+[lint.flake8-import-conventions]
 extend-aliases = { xarray = "xr" }
diff --git a/CHANGELOG.md b/CHANGELOG.md
index e6def3bce..eae44edb2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,11 +6,12 @@
 
 - rename (fix typo) argument to `lcs_child_in_parent` in `CoordinateSystemManager.add_cs`  \[{pull}`936`\].
 
-- replace usages of ``pkg_resources`` with ``importlib.metadata`` [#941]
+- replace usages of `pkg_resources` with `importlib.metadata` \[{pull}`941`\].
 
 ### Dependencies
 
 - pin `weldx-widgets>=0.2.3` for viz \[{pull}`939`\].
+- pin `pint>=0.21` \[{pull}`941`\].
 
 ## 0.6.8 (07.06.2024)
 
diff --git a/pyproject.toml b/pyproject.toml
index c78d5081b..4a33a85dd 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -51,7 +51,7 @@ dependencies = [
   "networkx>=2.8.2",
   "numpy>=1.20,<2",
   "pandas>=1.5",
-  "pint>=0.18",
+  "pint>=0.21",
   "pint-xarray>=0.3",
   "psutil",
   "scipy>=1.6.2",
diff --git a/weldx/config.py b/weldx/config.py
index ec3fd18b6..5afe2958d 100644
--- a/weldx/config.py
+++ b/weldx/config.py
@@ -2,10 +2,10 @@
 
 from __future__ import annotations
 
+import importlib.metadata
 from pathlib import Path
 
 import asdf
-import importlib.metadata
 import yaml
 from asdf.config import ResourceMappingProxy
 from asdf.versioning import AsdfVersion, split_tag_version
diff --git a/weldx/constants.py b/weldx/constants.py
index 1fe816d2c..fedb49a1f 100644
--- a/weldx/constants.py
+++ b/weldx/constants.py
@@ -16,7 +16,6 @@
 
 WELDX_UNIT_REGISTRY = pint.UnitRegistry(
     preprocessors=[
-        lambda string: string.replace("%", "percent"),  # allow %-sign
         lambda string: string.replace("Δ°", "delta_deg"),  # parse Δ° for temperature
     ],
     force_ndarray_like=True,
diff --git a/weldx/tests/_helpers.py b/weldx/tests/_helpers.py
index 1a06c4161..661388d55 100644
--- a/weldx/tests/_helpers.py
+++ b/weldx/tests/_helpers.py
@@ -1,10 +1,10 @@
 """Provides some utility functions for tests."""
 
+import importlib.metadata
 from typing import Any
 
 import numpy as np
 import pint
-import importlib.metadata
 
 from weldx.constants import Q_
 from weldx.geometry import _vector_is_close as vector_is_close
@@ -130,7 +130,9 @@ def matrix_is_close(mat_a, mat_b, abs_tol=1e-9) -> bool:
         return False
 
     atol_unit = 1.0
-    if isinstance(mat_b, pint.Quantity) and tuple(int(part) for part in importlib.metadata.version("pint").split(".")) >= (0, 21):
+    if isinstance(mat_b, pint.Quantity) and tuple(
+        int(part) for part in importlib.metadata.version("pint").split(".")
+    ) >= (0, 21):
         atol_unit = mat_b.u
 
     return np.all(np.isclose(mat_a, mat_b, atol=abs_tol * atol_unit)).__bool__()
diff --git a/weldx/tests/transformations/_util.py b/weldx/tests/transformations/_util.py
index 41afaab8c..904a456f7 100644
--- a/weldx/tests/transformations/_util.py
+++ b/weldx/tests/transformations/_util.py
@@ -3,7 +3,6 @@
 from typing import Any
 
 import numpy as np
-import importlib.metadata
 from xarray import DataArray
 
 import weldx.transformations as tf
@@ -78,9 +77,7 @@ def check_coordinate_system(
         lcs.orientation, orientation_expected, positive_orientation_expected
     )
 
-    atol_unit = 1.0
-    if tuple(int(part) for part in importlib.metadata.version("pint").split(".")) >= (0, 21):
-        atol_unit = coordinates_expected.u
+    atol_unit = coordinates_expected.u
 
     assert np.allclose(
         lcs.coordinates.data, coordinates_expected, atol=1e-9 * atol_unit