diff --git a/changelog.d/pr495.bugfix.rst b/changelog.d/pr495.bugfix.rst
new file mode 100644
index 0000000..ac01fa8
--- /dev/null
+++ b/changelog.d/pr495.bugfix.rst
@@ -0,0 +1 @@
+The type annotation of ``Version.is_valid()`` now includes its existing support for UTF-8 encoded byte strings.
diff --git a/src/semver/version.py b/src/semver/version.py
index 7ead382..6160bf7 100644
--- a/src/semver/version.py
+++ b/src/semver/version.py
@@ -789,7 +789,7 @@ def replace(self, **parts: Union[int, Optional[str]]) -> "Version":
             raise TypeError(error)
 
     @classmethod
-    def is_valid(cls, version: str) -> bool:
+    def is_valid(cls, version: String) -> bool:
         """
         Check if the string is a valid semver version.
 
@@ -798,7 +798,7 @@ def is_valid(cls, version: str) -> bool:
         .. versionchanged:: 3.0.0
            Renamed from :meth:`~semver.version.Version.isvalid`
 
-        :param version: the version string to check
+        :param version: the version string to check, as str or UTF-8 encoded bytes
         :return: True if the version string is a valid semver version, False
                  otherwise.
         """
diff --git a/tests/test_semver.py b/tests/test_semver.py
index 9978b94..fabf827 100644
--- a/tests/test_semver.py
+++ b/tests/test_semver.py
@@ -2,6 +2,8 @@
 
 from semver import Version
 
+UTF8_VERSION = "1.0.0"
+
 
 @pytest.mark.parametrize(
     "string,expected", [("rc", "rc"), ("rc.1", "rc.2"), ("2x", "3x")]
@@ -77,6 +79,19 @@ def test_should_versioninfo_isvalid():
     assert Version.is_valid("foo") is False
 
 
+@pytest.mark.parametrize(
+    "version,expected",
+    [
+        pytest.param(b"1.0.0", True, id="valid-bytes"),
+        pytest.param(b"foo", False, id="invalid-version-bytes"),
+        pytest.param(UTF8_VERSION.encode("UTF-8"), True, id="utf8-encoded-version"),
+        pytest.param(b"\xff", False, id="invalid-utf8"),
+    ],
+)
+def test_is_valid_bytes(version, expected):
+    assert Version.is_valid(version) is expected
+
+
 def test_versioninfo_compare_should_raise_when_passed_invalid_value():
     with pytest.raises(TypeError):
         Version(1, 2, 3).compare(4)