diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index e3a525f..64795bb 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ['3.9', '3.10', '3.11', '3.12', '3.13']
+        python-version: ['3.9', '3.10', '3.11', '3.12', '3.13', '3.14.0-alpha - 3.14']
     steps:
     - uses: actions/checkout@v4
     - uses: actions/setup-python@v5
diff --git a/README.md b/README.md
index fa71539..cd0bea0 100644
--- a/README.md
+++ b/README.md
@@ -106,7 +106,7 @@ If a type implements a custom `__instancecheck__`, it can opt-in to dispatch (wi
 ```python
 from multimethod import parametric
 
-Coroutine = parametric(Callable, asyncio.iscoroutinefunction)
+Coroutine = parametric(Callable, inspect.iscoroutinefunction)
 IntArray = parametric(array, typecode='i')
 ```
 
diff --git a/docs/examples.ipynb b/docs/examples.ipynb
index b8efafe..5aa4108 100644
--- a/docs/examples.ipynb
+++ b/docs/examples.ipynb
@@ -143,12 +143,13 @@
    "outputs": [],
    "source": [
     "import asyncio\n",
+    "import inspect\n",
     "import time\n",
     "from collections.abc import Callable\n",
     "from concurrent import futures\n",
     "from multimethod import parametric\n",
     "\n",
-    "Coroutine = parametric(Callable, asyncio.iscoroutinefunction)\n",
+    "Coroutine = parametric(Callable, inspect.iscoroutinefunction)\n",
     "\n",
     "\n",
     "@multimethod\n",
@@ -262,7 +263,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.12.3"
+   "version": "3.13.0"
   }
  },
  "nbformat": 4,
diff --git a/multimethod/__init__.py b/multimethod/__init__.py
index b762b49..c43647f 100644
--- a/multimethod/__init__.py
+++ b/multimethod/__init__.py
@@ -25,7 +25,7 @@ def get_args(tp) -> tuple:
 
 
 def get_mro(cls) -> tuple:  # `inspect.getmro` doesn't handle all cases
-    return type.mro(cls) if isinstance(cls, type) else cls.mro()
+    return tuple(type.mro(cls)) if isinstance(cls, type) else cls.mro()
 
 
 def common_bases(*bases):
diff --git a/pyproject.toml b/pyproject.toml
index 7076f78..f14cd1d 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -18,6 +18,7 @@ classifiers = [
     "Programming Language :: Python :: 3.11",
     "Programming Language :: Python :: 3.12",
     "Programming Language :: Python :: 3.13",
+    "Programming Language :: Python :: 3.14",
     "Topic :: Software Development :: Libraries :: Python Modules",
     "Typing :: Typed",
 ]
@@ -40,3 +41,6 @@ quote-style = "preserve"
 [tool.coverage.run]
 source = ["multimethod"]
 branch = true
+
+[tool.pytest.ini_options]
+markers = ["benchmark"]
diff --git a/tests/test_subscripts.py b/tests/test_subscripts.py
index abe5948..9aa651e 100644
--- a/tests/test_subscripts.py
+++ b/tests/test_subscripts.py
@@ -1,4 +1,5 @@
 import asyncio
+import inspect
 import sys
 import typing
 import pytest
@@ -130,10 +131,10 @@ def test_args():
 
 @pytest.mark.benchmark
 def test_parametric():
-    coro = parametric(Callable, asyncio.iscoroutinefunction)
+    coro = parametric(Callable, inspect.iscoroutinefunction)
     assert issubclass(coro, Callable)
     assert not issubclass(Callable, coro)
-    assert not issubclass(parametric(object, asyncio.iscoroutinefunction), coro)
+    assert not issubclass(parametric(object, inspect.iscoroutinefunction), coro)
     assert isinstance(asyncio.sleep, coro)
     assert not isinstance(lambda: None, coro)
     assert list(subtype.origins(coro)) == [Callable]