diff --git a/src/pluggy/_hooks.py b/src/pluggy/_hooks.py
index 3d232870..8bef18b0 100644
--- a/src/pluggy/_hooks.py
+++ b/src/pluggy/_hooks.py
@@ -36,6 +36,16 @@
 ]
 _HookImplFunction: TypeAlias = Callable[..., _T | Generator[None, Result[_T], None]]
 
+if sys.version_info >= (3, 14):
+    from annotationlib import Format
+
+    def _signature(func: Callable[..., object]) -> inspect.Signature:
+        return inspect.signature(func, annotation_format=Format.STRING)
+else:
+
+    def _signature(func: Callable[..., object]) -> inspect.Signature:
+        return inspect.signature(func)
+
 
 class HookspecOpts(TypedDict):
     """Options for a hook specification."""
@@ -310,7 +320,7 @@ def varnames(func: object) -> tuple[tuple[str, ...], tuple[str, ...]]:
 
     try:
         # func MUST be a function or method here or we won't parse any args.
-        sig = inspect.signature(
+        sig = _signature(
             func.__func__ if inspect.ismethod(func) else func  # type:ignore[arg-type]
         )
     except TypeError:  # pragma: no cover
diff --git a/src/pluggy/_manager.py b/src/pluggy/_manager.py
index c20105c8..88f1d2cb 100644
--- a/src/pluggy/_manager.py
+++ b/src/pluggy/_manager.py
@@ -18,6 +18,7 @@
 from ._hooks import _HookImplFunction
 from ._hooks import _Namespace
 from ._hooks import _Plugin
+from ._hooks import _signature
 from ._hooks import _SubsetHookCaller
 from ._hooks import HookCaller
 from ._hooks import HookImpl
@@ -522,4 +523,4 @@ def subset_hook_caller(
 
 
 def _formatdef(func: Callable[..., object]) -> str:
-    return f"{func.__name__}{inspect.signature(func)}"
+    return f"{func.__name__}{_signature(func)}"
diff --git a/testing/test_helpers.py b/testing/test_helpers.py
index a08e3d7a..17fdd243 100644
--- a/testing/test_helpers.py
+++ b/testing/test_helpers.py
@@ -1,13 +1,20 @@
 from collections.abc import Callable
 from functools import wraps
+import sys
 from typing import Any
 from typing import cast
+from typing import TYPE_CHECKING
 from typing import TypeVar
 
 from pluggy._hooks import varnames
 from pluggy._manager import _formatdef
 
 
+if TYPE_CHECKING:
+    # Cannot use typing.Tuple due to pyupgrade replacing it with tuple
+    from non_existent_module import Tuple
+
+
 def test_varnames() -> None:
     def f(x) -> None:
         i = 3  # noqa #pragma: no cover
@@ -90,6 +97,32 @@ def function4(arg1, *args, **kwargs):
     assert _formatdef(function4) == "function4(arg1, *args, **kwargs)"
 
 
+def test_varnames_with_annotations() -> None:
+    if sys.version_info >= (3, 14):
+
+        def hook(arg1: Tuple[int]) -> None:  # type: ignore[no-any-unimported]
+            pass
+    else:
+
+        def hook(arg1: "Tuple[int]") -> "None":  # type: ignore[no-any-unimported]
+            pass
+
+    assert varnames(hook) == (("arg1",), ())
+
+
+def test_formatdef_with_annotations() -> None:
+    if sys.version_info >= (3, 14):
+
+        def hook(arg1: Tuple[int]) -> None:  # type: ignore[no-any-unimported]
+            pass
+    else:
+
+        def hook(arg1: "Tuple[int]") -> "None":  # type: ignore[no-any-unimported]
+            pass
+
+    assert _formatdef(hook) == "hook(arg1: 'Tuple[int]') -> 'None'"
+
+
 def test_varnames_decorator() -> None:
     F = TypeVar("F", bound=Callable[..., Any])