diff --git a/pyproject.toml b/pyproject.toml
index eac1682a..b1d7fd51 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -29,7 +29,7 @@ classifiers = [
 dependencies = [
     "CacheControl[filecache] >= 0.13.0",
     "cyclonedx-python-lib >= 5,< 12",
-    "packaging>=23.0.0",                 # https://github.com/pypa/pip-audit/issues/464
+    "packaging>=23.0.0",
     "pip-api>=0.0.28",
     "pip-requirements-parser>=32.0.0",
     "requests >= 2.31.0",
@@ -44,7 +44,11 @@ requires-python = ">=3.10"
 cov = [
     "coverage[toml] ~= 7.0, != 7.3.3", # https://github.com/nedbat/coveragepy/issues/1713
 ]
-test = ["pretend", "pytest", "pip-audit[cov]"]
+test = [
+    "pretend",
+    "pytest",
+    "pip-audit[cov]"
+]
 lint = [
     "ruff >= 0.14",
     "interrogate ~= 1.6",
diff --git a/test/dependency_source/test_requirement.py b/test/dependency_source/test_requirement.py
index b8873f83..eb978d17 100644
--- a/test/dependency_source/test_requirement.py
+++ b/test/dependency_source/test_requirement.py
@@ -889,3 +889,21 @@ def test_requirement_source_disable_pip_editable_without_egg_fragment(req_file):
         )
         in specs
     )
+
+
+def test_requirement_source_non_normalized_version(req_file):
+    """
+    This test verifies the fix for issue https://github.com/pypa/pip-audit/issues/464,
+    where non-normalized version strings in requirements files could cause parsing errors.
+    With packaging>=23.0.0, these versions should be parsed and normalized correctly.
+    """
+    source = _init_requirement(
+        [(req_file(), "setuptools==80.9.1.0")], disable_pip=True, no_deps=True
+    )
+
+    specs = list(source.collect())
+    assert len(specs) == 1
+    assert isinstance(specs[0], ResolvedDependency)
+    assert specs[0].name == "setuptools"
+    # Both versions should be considered equal
+    assert specs[0].version == Version("80.9.1") == Version("80.9.1.0")