diff --git a/tests/test_auto_attribs__py3.py b/tests/test_auto_attribs__py3.py
index 67b3ff8..8241f9d 100644
--- a/tests/test_auto_attribs__py3.py
+++ b/tests/test_auto_attribs__py3.py
@@ -28,9 +28,13 @@ from attrs_strict import type_validator
             None,
             0xBAD,
             "Value of value 2989 is not of type {}".format(
-                "typing.Optional[str]"
-                if sys.version_info == (2, 7) or sys.version_info > (3, 9)
-                else "typing.Union[str, NoneType]"
+                "str | None"
+                if sys.version_info >= (3, 14)
+                else (
+                    "typing.Optional[str]"
+                    if sys.version_info == (2, 7) or sys.version_info > (3, 9)
+                    else "typing.Union[str, NoneType]"
+                )
             ),
         ),
     ],
@@ -75,9 +79,13 @@ def test_recursive():
     Self(Self())
     Self(Self(None))
     type_repr = (
-        "typing.Optional[test_auto_attribs__py3.Self]"
-        if sys.version_info == (2, 7) or sys.version_info > (3, 9)
-        else "typing.Union[test_auto_attribs__py3.Self, NoneType]"
+        "test_auto_attribs__py3.Self | None"
+        if sys.version_info >= (3, 14)
+        else (
+            "typing.Optional[test_auto_attribs__py3.Self]"
+            if sys.version_info == (2, 7) or sys.version_info > (3, 9)
+            else "typing.Union[test_auto_attribs__py3.Self, NoneType]"
+        )
     )
     msg = f"Value of parent 17 is not of type {type_repr}"
     with pytest.raises(ValueError, match=re.escape(msg)):
diff --git a/tests/test_union.py b/tests/test_union.py
index e1b11a9..49d7c20 100644
--- a/tests/test_union.py
+++ b/tests/test_union.py
@@ -16,16 +16,26 @@ from attrs_strict import type_validator
         (
             2.0,
             Union[int, str],
-            "Value of foo 2.0 is not of type typing.Union[int, str]",
+            (
+                "Value of foo 2.0 is not of type {}".format(
+                    "int | str"
+                    if sys.version_info >= (3, 14)
+                    else "typing.Union[int, str]"
+                )
+            ),
         ),
         (
             [1, 2, "p"],
             List[Union[None, int]],
             (
                 "Value of foo p is not of type {} in [1, 2, 'p']".format(
-                    "typing.Optional[int]"
-                    if sys.version_info >= (3, 9)
-                    else "typing.Union[NoneType, int]"
+                    "None | int"
+                    if sys.version_info >= (3, 14)
+                    else (
+                        "typing.Optional[int]"
+                        if sys.version_info >= (3, 9)
+                        else "typing.Union[NoneType, int]"
+                    )
                 )
             ),
         ),