---
 pyproject.toml    |    3 +--
 tests/test_api.py |    5 -----
 2 files changed, 1 insertion(+), 7 deletions(-)

--- a/pyproject.toml
+++ b/pyproject.toml
@@ -51,8 +51,7 @@ docs = [
 test = [
     "testpath",
     "pytest",
-    "pre-commit",
-    "pep440"
+    "pre-commit"
 ]
 
 [project.scripts]
--- a/tests/test_api.py
+++ b/tests/test_api.py
@@ -10,7 +10,6 @@ from tempfile import TemporaryDirectory
 from typing import Any, Dict
 
 from jsonschema import ValidationError
-from pep440 import is_canonical
 
 from nbformat import __version__ as nbf_version
 from nbformat import current_nbformat, read, write, writes
@@ -20,10 +19,6 @@ from nbformat.validator import isvalid
 from .base import TestsBase
 
 
-def test_canonical_version():
-    assert is_canonical(nbf_version)
-
-
 class TestAPI(TestsBase):
     def test_read(self):
         """Can older notebooks be opened and automatically converted to the current