diff --git a/grudge/models/euler.py b/grudge/models/euler.py
index 23bfc4b3..f35c132d 100644
--- a/grudge/models/euler.py
+++ b/grudge/models/euler.py
@@ -50,7 +50,7 @@
 THE SOFTWARE.
 """
 
-from abc import ABCMeta, abstractmethod
+from abc import ABC, abstractmethod
 from dataclasses import dataclass
 from typing import TYPE_CHECKING
 
@@ -172,7 +172,7 @@ def compute_wavespeed(actx: ArrayContext, cv_state: ConservedEulerField, gamma=1
 
 # {{{ Boundary condition types
 
-class InviscidBCObject(metaclass=ABCMeta):
+class InviscidBCObject(ABC):
 
     def __init__(self, *, prescribed_state=None) -> None:
         self.prescribed_state = prescribed_state
diff --git a/pyproject.toml b/pyproject.toml
index 4bb84a9f..c8f34db3 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -94,6 +94,7 @@ extend-ignore = [
     "tab-after-comma",
     "module-import-not-at-top-of-file",
     "non-empty-init-module",
+    "pytest-parameter-with-default-argument",
 ]
 
 [tool.ruff.lint.flake8-quotes]