diff --git a/docs/source/conf.py b/docs/source/conf.py
index c06b691413..5037c04b1b 100644
--- a/docs/source/conf.py
+++ b/docs/source/conf.py
@@ -8,14 +8,22 @@
 import importlib
 import logging
 import os
+import pkgutil
 import sys
 import typing
 from typing import TYPE_CHECKING
 
+# NB: a private module of ``sphinx-autodoc-typehints``, used deliberately -- see
+# ``bind_type_checking_names`` below for what it buys and why reimplementing it
+# here would be worse. If a future release moves it the import fails loudly at
+# build time, which is the outcome to want: the alternative is a build that
+# silently goes back to emitting unresolvable annotations.
+from sphinx_autodoc_typehints._resolver import resolve_type_guarded_imports
+
 import pcapkit
 
 if TYPE_CHECKING:
-    from typing import Any, Dict, List
+    from typing import Any, Dict, List, Optional
     from sphinx.application import Sphinx
 
 os.environ['PCAPKIT_SPHINX'] = '1'
@@ -137,6 +145,16 @@
 always_document_param_types = False
 typehints_document_rtype = True
 
+# NB: a ``:rtype: None`` field says nothing the rendered signature has not already
+# said, and injecting it is actively harmful in one measured case: for a docstring
+# whose field list is followed by a directive,
+# ``sphinx_autodoc_typehints`` computes an insertion point *inside* that directive
+# and splits it from its content. ``PCAP_CT.run`` was the case -- its trailing
+# ``Note:`` lost its body and the build reported ``Content block expected for the
+# "note" directive; none found``. Skipping the ``None`` returns removes the noise
+# and the corruption together; non-``None`` returns are still documented.
+typehints_document_rtype_none = False
+
 toc_object_entries = False
 
 # Add any paths that contain templates here, relative to this directory.
@@ -207,6 +225,111 @@ def maybe_skip_member(app: 'Sphinx', what: str, name: str,  # pylint: disable=un
     return skip
 
 
+def bind_type_checking_names(app: 'Sphinx') -> None:
+    """Execute every ``pcapkit`` module's ``if TYPE_CHECKING:`` block.
+
+    Annotations throughout the package are quoted and their types imported only
+    under :data:`~typing.TYPE_CHECKING`, which is right at runtime and awkward
+    here. Autodoc reads a class attribute's type with
+    :func:`typing.get_type_hints`, and a single unresolvable name makes that raise
+    :exc:`NameError` for the *whole class*; Sphinx then falls back to the raw
+    ``__annotations__`` strings. So ``pre: 'ToSPrecedence'`` was rendered as the
+    bare word ``ToSPrecedence``, which the Python domain has to resolve by
+    suffix-matching -- and both :class:`pcapkit.const.ipv4.tos_pre.ToSPrecedence`
+    and its generator :class:`pcapkit.vendor.ipv4.tos_pre.ToSPrecedence` end in
+    it. That is where the bulk of the ``more than one target found`` warnings came
+    from, and roughly half of the links Sphinx picked went to the vendor crawler
+    rather than to the enumeration the attribute actually holds.
+
+    Binding the guarded names into each module up front lets
+    :func:`typing.get_type_hints` succeed, so the annotation is stringified from
+    the resolved object and carries its full dotted path. Nothing is suppressed:
+    the references are qualified rather than silenced.
+
+    ``sphinx-autodoc-typehints`` already does this per module, lazily, for the
+    objects it processes -- but it skips classes outright, since it keys off
+    ``__globals__`` which a class does not have, so class attributes never
+    benefited. Its implementation is reused rather than rewritten because it
+    executes the block one statement at a time, so an unimportable optional
+    dependency (``pcap``, ``pcapfile``) cannot strand the names declared after it.
+
+    One consequence is worth knowing before it is met as a mystery: making the
+    annotations resolvable also makes a malformed one **fatal**. A quoted
+    annotation with stray whitespace inside the quotes -- ``rank: ' int'``, the
+    space that belongs after the colon typed one character late -- is meaningless
+    to a type checker and was previously harmless here, because these annotations
+    failed earlier with :exc:`NameError`, which
+    :func:`sphinx.util.typing.get_type_hints` catches. Now they resolve, and Python
+    3.14's :mod:`annotationlib` rejects the leading space with a
+    :exc:`SyntaxError` that :func:`~sphinx.util.typing.get_type_hints` does *not*
+    catch, so it aborts the whole build. Two such annotations existed and both are
+    fixed at source; a third would stop the build rather than be worked around
+    here, which is the right way round for a typo.
+
+    Args:
+        app: Sphinx application.
+
+    """
+    for info in pkgutil.walk_packages(pcapkit.__path__, 'pcapkit.',
+                                      onerror=lambda name: None):
+        try:
+            module = importlib.import_module(info.name)
+        except Exception as exc:  # pylint: disable=broad-except
+            # A module that cannot be imported has no documentable annotations
+            # either, so this is not worth failing the build over -- but it is
+            # worth saying out loud rather than passing silently.
+            logger.info('skipped unimportable module %s: %s', info.name, exc)
+            continue
+        resolve_type_guarded_imports(app.config.autodoc_mock_imports, module)
+
+
+def claim_attribute_signature(app: 'Sphinx', what: str, name: str,  # pylint: disable=unused-argument
+                              obj: 'Any', options: 'Dict[str, Any]',  # pylint: disable=unused-argument
+                              signature: 'Optional[str]',  # pylint: disable=unused-argument
+                              return_annotation: 'Optional[str]') -> 'Optional[tuple]':  # pylint: disable=unused-argument
+    """Stop a class-valued attribute being given the class's own signature.
+
+    Several class attributes here hold a *class* as their value --
+    :attr:`Protocol.__schema__ <pcapkit.protocols.protocol.Protocol.__schema__>` and
+    the ``__protocol_type__`` of each reassembly and flow-tracing class. Autodoc
+    documents them as attributes, so it collects no signature for them, but
+    ``sphinx_autodoc_typehints`` keys its own handler off ``callable(obj)`` alone,
+    sees a class, and hands one back. Sphinx 9.1 then stores it with
+    ``signatures[0] = ...`` on a list it never populated, which raises
+    ``IndexError: list assignment index out of range`` -- and autodoc turns that
+    into ``error while formatting signature for ...`` and drops the member from the
+    page entirely.
+
+    Claiming the event first is what prevents that. The returned value has to be
+    non-:data:`None` to win ``emit_firstresult`` yet must not look like a
+    ``(args, retann)`` pair, so it is the empty tuple: falsy, and of the wrong
+    length for the ``len(result) == 2`` guard Sphinx applies before unpacking. An
+    attribute has no signature of its own to lose, so nothing is suppressed here
+    beyond a value that was never meaningful.
+
+    ``callable(obj)`` keeps this off ordinary attributes and off properties, whose
+    ``obj`` is the :class:`property` itself and therefore not callable -- those
+    already resolve correctly and are left alone.
+
+    Args:
+        app: Sphinx application.
+        what: Type of the object being documented.
+        name: Fully qualified name of the object.
+        obj: The object itself.
+        options: Directive options.
+        signature: Signature autodoc has so far, if any.
+        return_annotation: Return annotation autodoc has so far, if any.
+
+    Returns:
+        The empty tuple for a class-valued attribute, to claim the event without
+        recording a signature; :data:`None` otherwise, to let other handlers run.
+
+    """
+    if what in {'attribute', 'property'} and callable(obj):
+        return ()
+    return None
+
+
 def remove_module_docstring(app: 'Sphinx', what: str, name: str,  # pylint: disable=unused-argument
                             obj: 'Any', options: 'Dict[str, Any]', lines: 'List[str]') -> None:  # pylint: disable=unused-argument
     if what == "module" and "pcapkit" in name:
@@ -243,7 +366,12 @@ def source_read(app: 'Sphinx', docname: str, source_text: str) -> 'None':  # pyl
 def setup(app: 'Sphinx') -> None:
     #app.connect('autodoc-process-docstring', process_docstring, 0)
     #app.connect("autodoc-process-docstring", remove_module_docstring)
+    app.connect('builder-inited', bind_type_checking_names)
     app.connect('autodoc-skip-member', maybe_skip_member)
+    # NB: below ``sphinx_autodoc_typehints``, which connects at the default 500 and
+    # would otherwise win the tie on registration order -- conf.py's ``setup`` runs
+    # after the extensions in ``extensions`` have been set up.
+    app.connect('autodoc-process-signature', claim_attribute_signature, priority=400)
     #app.connect('source-read', source_read)
     #app.connect('autodoc-process-docstring', process_fields)
 
diff --git a/docs/source/pcapkit/foundation/traceflow/traceflow.rst b/docs/source/pcapkit/foundation/traceflow/traceflow.rst
index 5e4cb55c73..568281a4d5 100644
--- a/docs/source/pcapkit/foundation/traceflow/traceflow.rst
+++ b/docs/source/pcapkit/foundation/traceflow/traceflow.rst
@@ -27,7 +27,7 @@ which is an abstract base class for all flow tracing classes.
          value can be set by :attr:`__protocol_name__` class attribute.
 
    .. property:: protocol
-      :type: Type[Protocol]
+      :type: typing.Type[pcapkit.protocols.protocol.ProtocolBase]
 
       Protocol of current class.
 
@@ -76,22 +76,22 @@ Internal Definitions
 Type Variables
 --------------
 
-.. data:: pcapkit.foundation.traceflow.traceflow._DT
+.. data:: _DT
    :type: typing.Any
 
    Buffer ID data structure.
 
-.. data:: pcapkit.foundation.traceflow.traceflow._BT
+.. data:: _BT
    :type: pcapkit.corekit.infoclass.Info
 
    Buffer data structure.
 
-.. data:: pcapkit.foundation.traceflow.traceflow._IT
+.. data:: _IT
    :type: pcapkit.corekit.infoclass.Info
 
    Index data structure.
 
-.. data:: pcapkit.foundation.traceflow.traceflow._PT
+.. data:: _PT
    :type: pcapkit.corekit.infoclass.Info
 
    Packet data structure.
diff --git a/docs/source/pcapkit/protocols/internet/ipv4.rst b/docs/source/pcapkit/protocols/internet/ipv4.rst
index ddd426da93..fbac300ab3 100644
--- a/docs/source/pcapkit/protocols/internet/ipv4.rst
+++ b/docs/source/pcapkit/protocols/internet/ipv4.rst
@@ -219,7 +219,7 @@ Data Models
    :show-inheritance:
 
    .. attribute:: del
-      :type: ToSDelay
+      :type: pcapkit.const.ipv4.tos_del.ToSDelay
 
       Delay.
 
@@ -241,7 +241,7 @@ Data Models
    :show-inheritance:
 
    .. attribute:: class
-      :type: OptionClass
+      :type: pcapkit.const.ipv4.option_class.OptionClass
 
       Option class.
 
diff --git a/pcapkit/foundation/extraction.py b/pcapkit/foundation/extraction.py
index 89ed941303..2c3e89e5fb 100644
--- a/pcapkit/foundation/extraction.py
+++ b/pcapkit/foundation/extraction.py
@@ -52,6 +52,7 @@
     from scapy.packet import Packet as ScapyPacket
     from typing_extensions import Literal
 
+    from pcapkit.corekit.context import ProtocolContext
     from pcapkit.foundation.reassembly.ipv4 import IPv4 as IPv4_Reassembly
     from pcapkit.foundation.reassembly.ipv6 import IPv6 as IPv6_Reassembly
     from pcapkit.foundation.reassembly.tcp import TCP as TCP_Reassembly
diff --git a/pcapkit/foundation/reassembly/reassembly.py b/pcapkit/foundation/reassembly/reassembly.py
index 92bad08a53..7be2ef42f8 100644
--- a/pcapkit/foundation/reassembly/reassembly.py
+++ b/pcapkit/foundation/reassembly/reassembly.py
@@ -19,6 +19,20 @@
 from pcapkit.utilities.exceptions import UnsupportedCall
 from pcapkit.utilities.logging import get_logger
 
+# NB: declared above the ``TYPE_CHECKING`` block, not below it, so that
+# ``CallbackFn`` can name ``_DT`` outright. As a quoted forward reference it was
+# resolvable only from this module's namespace, and every module that spells
+# ``CallbackFn`` in an annotation -- ``pcapkit.foundation.registry.foundation``
+# does -- has to evaluate the alias in its own.
+# packet
+_PT = TypeVar('_PT', bound='Info')
+# datagram
+_DT = TypeVar('_DT', bound='Info')
+# buffer ID
+_IT = TypeVar('_IT', bound='tuple')
+# buffer
+_BT = TypeVar('_BT', bound='Info')
+
 if TYPE_CHECKING:
     from typing import Any, Callable, Optional, Type
 
@@ -27,7 +41,7 @@
     from pcapkit.corekit.infoclass import Info
     from pcapkit.protocols.protocol import ProtocolBase as Protocol
 
-    CallbackFn = Callable[[list['_DT']], None]
+    CallbackFn = Callable[[list[_DT]], None]
 
 __all__ = ['Reassembly']
 
@@ -35,15 +49,6 @@
 #: :data:`pcapkit.utilities.logging.logger`.
 logger = get_logger(__name__)
 
-# packet
-_PT = TypeVar('_PT', bound='Info')
-# datagram
-_DT = TypeVar('_DT', bound='Info')
-# buffer ID
-_IT = TypeVar('_IT', bound='tuple')
-# buffer
-_BT = TypeVar('_BT', bound='Info')
-
 
 class ReassemblyMeta(abc.ABCMeta):
     """Meta class to add dynamic support to :class:`Reassembly`.
diff --git a/pcapkit/foundation/traceflow/traceflow.py b/pcapkit/foundation/traceflow/traceflow.py
index b54d97e903..fb4a868094 100644
--- a/pcapkit/foundation/traceflow/traceflow.py
+++ b/pcapkit/foundation/traceflow/traceflow.py
@@ -32,6 +32,16 @@
 #: :data:`pcapkit.utilities.logging.logger`.
 logger = get_logger(__name__)
 
+# NB: declared above the ``TYPE_CHECKING`` block, not below it, so that
+# ``CallbackFn`` can name ``_IT`` outright. As a quoted forward reference it was
+# resolvable only from this module's namespace, and every module that spells
+# ``CallbackFn`` in an annotation -- ``pcapkit.foundation.registry.foundation``
+# does -- has to evaluate the alias in its own.
+_DT = TypeVar('_DT')
+_BT = TypeVar('_BT', bound='Info')
+_IT = TypeVar('_IT', bound='Info')
+_PT = TypeVar('_PT', bound='Info')
+
 if TYPE_CHECKING:
     from typing import Any, Callable, DefaultDict, Optional, Type
 
@@ -40,12 +50,7 @@
     from pcapkit.corekit.infoclass import Info
     from pcapkit.protocols.protocol import ProtocolBase as Protocol
 
-    CallbackFn = Callable[['_IT'], None]
-
-_DT = TypeVar('_DT')
-_BT = TypeVar('_BT', bound='Info')
-_IT = TypeVar('_IT', bound='Info')
-_PT = TypeVar('_PT', bound='Info')
+    CallbackFn = Callable[[_IT], None]
 
 
 class TraceFlowMeta(abc.ABCMeta):
diff --git a/pcapkit/protocols/__init__.py b/pcapkit/protocols/__init__.py
index 3e61edeb55..b457493e45 100644
--- a/pcapkit/protocols/__init__.py
+++ b/pcapkit/protocols/__init__.py
@@ -68,7 +68,7 @@
     'HTTP', 'HTTPv1', 'HTTPv2',
 ]
 
-#: dict[str, Type[Protocol]]: Protocol registry.
+#: dict[str, ~typing.Type[Protocol]]: Protocol registry.
 __proto__ = {}  # type: dict[str, Type[ProtocolBase]]
 for name in __all__:
     __proto__[name.upper()] = globals()[name]
diff --git a/pcapkit/protocols/application/httpv2.py b/pcapkit/protocols/application/httpv2.py
index 94628a1df8..f00023f407 100644
--- a/pcapkit/protocols/application/httpv2.py
+++ b/pcapkit/protocols/application/httpv2.py
@@ -83,8 +83,12 @@
     Flags = Schema_FrameType.Flags
 
     FrameParser = Callable[[Schema_FrameType, NamedArg(Schema_HTTP, 'header')], Data_HTTP]
+    # NB: ``Flags`` is bound just above, so it goes in unquoted. Quoting it left a
+    # bare ``ForwardRef('Flags')`` inside the alias, which every *other* module
+    # that spells ``FrameConstructor`` in an annotation then had to resolve in its
+    # own namespace -- where the name does not exist.
     FrameConstructor = Callable[[DefaultArg(Optional[Data_HTTP]),
-                                 KwArg(Any)], Tuple[Schema_FrameType, 'Flags']]
+                                 KwArg(Any)], Tuple[Schema_FrameType, Flags]]
 
 __all__ = ['HTTP']
 
diff --git a/pcapkit/protocols/data/internet/hopopt.py b/pcapkit/protocols/data/internet/hopopt.py
index fbf155f5b5..6a479c65a3 100644
--- a/pcapkit/protocols/data/internet/hopopt.py
+++ b/pcapkit/protocols/data/internet/hopopt.py
@@ -240,7 +240,7 @@ class RPLOption(Option):
     #: RPL instance ID.
     id: 'int'
     #: Sender rank.
-    rank:' int'
+    rank: 'int'
 
     if TYPE_CHECKING:
         def __init__(self, type: 'Enum_Option', action: 'int', change: 'bool', length: 'int', flags: 'RPLFlags', id: 'int', rank: 'int') -> 'None': ...  # pylint: disable=super-init-not-called,unused-argument,redefined-builtin,multiple-statements,line-too-long
diff --git a/pcapkit/protocols/data/internet/ipv6_opts.py b/pcapkit/protocols/data/internet/ipv6_opts.py
index 91258064e7..afedab2a48 100644
--- a/pcapkit/protocols/data/internet/ipv6_opts.py
+++ b/pcapkit/protocols/data/internet/ipv6_opts.py
@@ -251,7 +251,7 @@ class RPLOption(Option):
     #: RPL instance ID.
     id: 'int'
     #: Sender rank.
-    rank: ' int'
+    rank: 'int'
 
     if TYPE_CHECKING:
         def __init__(self, type: 'Enum_Option', action: 'int', change: 'bool', length: 'int', flags: 'RPLFlags', id: 'int',
diff --git a/pcapkit/protocols/internet/internet.py b/pcapkit/protocols/internet/internet.py
index d698b7dc04..2630c66ac7 100644
--- a/pcapkit/protocols/internet/internet.py
+++ b/pcapkit/protocols/internet/internet.py
@@ -83,7 +83,7 @@ class Internet(Protocol[_PT, _ST], Generic[_PT, _ST]):  # pylint: disable=abstra
     #: Layer of protocol.
     __layer__ = 'Internet'  # type: Literal['Internet']
 
-    #: DefaultDict[int, ModuleDescriptor[Protocol] | Type[Protocol]]: Protocol index mapping for decoding next layer,
+    #: DefaultDict[int, ModuleDescriptor[Protocol] | ~typing.Type[Protocol]]: Protocol index mapping for decoding next layer,
     #: c.f. :meth:`self._decode_next_layer <pcapkit.protocols.internet.internet.Internet._decode_next_layer>`
     #: & :meth:`self._import_next_layer <pcapkit.protocols.internet.internet.Internet._import_next_layer>`.
     __proto__ = collections.defaultdict(
diff --git a/pcapkit/protocols/internet/ipv6.py b/pcapkit/protocols/internet/ipv6.py
index 1d0c94556d..1569495142 100644
--- a/pcapkit/protocols/internet/ipv6.py
+++ b/pcapkit/protocols/internet/ipv6.py
@@ -48,6 +48,7 @@
     from typing_extensions import Literal
 
     from pcapkit.protocols.protocol import ProtocolBase as Protocol
+    from pcapkit.protocols.schema.schema import Schema
 
 __all__ = ['IPv6']
 
diff --git a/pcapkit/protocols/internet/ipv6_route.py b/pcapkit/protocols/internet/ipv6_route.py
index f8bae07d84..179196c5fa 100644
--- a/pcapkit/protocols/internet/ipv6_route.py
+++ b/pcapkit/protocols/internet/ipv6_route.py
@@ -48,12 +48,14 @@
 if TYPE_CHECKING:
     from enum import IntEnum as StdlibEnum
     from ipaddress import IPv6Address
-    from typing import IO, Any, Callable, DefaultDict, Optional, Type
+    from typing import IO, Any, Callable, DefaultDict, NoReturn, Optional, Type
 
     from aenum import IntEnum as AenumEnum
     from mypy_extensions import DefaultArg, KwArg, NamedArg
     from typing_extensions import Literal
 
+    from pcapkit.corekit.protochain import ProtoChain
+    from pcapkit.protocols.protocol import ProtocolBase as Protocol
     from pcapkit.protocols.schema.internet.ipv6_route import RoutingType as Schema_RoutingType
 
     TypeParser = Callable[[Schema_RoutingType, NamedArg(Schema_IPv6_Route, 'header')], Data_IPv6_Route]
diff --git a/pcapkit/protocols/link/link.py b/pcapkit/protocols/link/link.py
index e348c7d3ef..e5201c3e6c 100644
--- a/pcapkit/protocols/link/link.py
+++ b/pcapkit/protocols/link/link.py
@@ -68,7 +68,7 @@ class Link(Protocol[_PT, _ST], Generic[_PT, _ST]):  # pylint: disable=abstract-m
     #: Layer of protocol.
     __layer__ = 'Link'  # type: Literal['Link']
 
-    #: DefaultDict[int, ModuleDescriptor[Protocol] | Type[Protocol]]: Protocol index mapping for decoding next layer,
+    #: DefaultDict[int, ModuleDescriptor[Protocol] | ~typing.Type[Protocol]]: Protocol index mapping for decoding next layer,
     #: c.f. :meth:`self._decode_next_layer <pcapkit.protocols.protocol.Protocol._decode_next_layer>`
     #: & :meth:`self._import_next_layer <pcapkit.protocols.protocol.Protocol._import_next_layer>`.
     __proto__ = collections.defaultdict(
diff --git a/pcapkit/protocols/misc/pcap/frame.py b/pcapkit/protocols/misc/pcap/frame.py
index a527776196..bdf2f8c7a5 100644
--- a/pcapkit/protocols/misc/pcap/frame.py
+++ b/pcapkit/protocols/misc/pcap/frame.py
@@ -82,7 +82,7 @@ class Frame(Protocol[Data_Frame, Schema_Frame],
     # Defaults.
     ##########################################################################
 
-    #: DefaultDict[Enum_LinkType, ModuleDescriptor[Protocol] | Type[Protocol]]: Protocol index mapping for
+    #: DefaultDict[Enum_LinkType, ModuleDescriptor[Protocol] | ~typing.Type[Protocol]]: Protocol index mapping for
     #: decoding next layer, c.f. :meth:`self._decode_next_layer <pcapkit.protocols.protocol.Protocol._decode_next_layer>`
     #: & :meth:`self._import_next_layer <pcapkit.protocols.protocol.Protocol._import_next_layer>`.
     #: The values should be a tuple representing the module name and class name, or
diff --git a/pcapkit/protocols/misc/pcapng.py b/pcapkit/protocols/misc/pcapng.py
index 61ab0764d3..74f4814b34 100644
--- a/pcapkit/protocols/misc/pcapng.py
+++ b/pcapkit/protocols/misc/pcapng.py
@@ -548,7 +548,7 @@ class PCAPNG(Protocol[Data_PCAPNG, Schema_PCAPNG],
     # Defaults.
     ##########################################################################
 
-    #: DefaultDict[Enum_LinkType, ModuleDescriptor[Protocol] | Type[Protocol]]: Protocol index mapping for
+    #: DefaultDict[Enum_LinkType, ModuleDescriptor[Protocol] | ~typing.Type[Protocol]]: Protocol index mapping for
     #: decoding next layer, c.f. :meth:`self._decode_next_layer <pcapkit.protocols.protocol.Protocol._decode_next_layer>`
     #: & :meth:`self._import_next_layer <pcapkit.protocols.protocol.Protocol._import_next_layer>`.
     #: The values should be a tuple representing the module name and class name,
diff --git a/pcapkit/protocols/transport/sctp.py b/pcapkit/protocols/transport/sctp.py
index 5a8b8103ac..5b1cba3848 100644
--- a/pcapkit/protocols/transport/sctp.py
+++ b/pcapkit/protocols/transport/sctp.py
@@ -332,7 +332,7 @@ class SCTP(Transport[Data_SCTP, Schema_SCTP],
     #: Payload protocol identifier of the first DATA chunk found in the packet.
     _ppid = None  # type: Optional[Enum_PayloadProtocolIdentifier]
 
-    #: DefaultDict[int, ModuleDescriptor[Protocol] | Type[Protocol]]: Protocol
+    #: DefaultDict[int, ModuleDescriptor[Protocol] | ~typing.Type[Protocol]]: Protocol
     #: index mapping for decoding next layer, c.f.
     #: :meth:`self._decode_next_layer <pcapkit.protocols.transport.sctp.SCTP._decode_next_layer>`
     #: & :meth:`self._import_next_layer <pcapkit.protocols.protocol.Protocol._import_next_layer>`.
diff --git a/pcapkit/protocols/transport/tcp.py b/pcapkit/protocols/transport/tcp.py
index e8131eb61e..71d9de2387 100644
--- a/pcapkit/protocols/transport/tcp.py
+++ b/pcapkit/protocols/transport/tcp.py
@@ -302,7 +302,7 @@ class TCP(Transport[Data_TCP, Schema_TCP],
     # Defaults.
     ##########################################################################
 
-    #: DefaultDict[int, ModuleDescriptor[Protocol] | Type[Protocol]]: Protocol
+    #: DefaultDict[int, ModuleDescriptor[Protocol] | ~typing.Type[Protocol]]: Protocol
     #: index mapping for decoding next layer, c.f.
     #: :meth:`self._decode_next_layer <pcapkit.protocols.transport.transport.Transport._decode_next_layer>`
     #: & :meth:`self._import_next_layer <pcapkit.protocols.protocol.Protocol._import_next_layer>`.
diff --git a/pcapkit/protocols/transport/udp.py b/pcapkit/protocols/transport/udp.py
index 78873bd5cc..e654131f95 100644
--- a/pcapkit/protocols/transport/udp.py
+++ b/pcapkit/protocols/transport/udp.py
@@ -65,7 +65,7 @@ class UDP(Transport[Data_UDP, Schema_UDP],
     # Defaults.
     ##########################################################################
 
-    #: DefaultDict[int, ModuleDescriptor[Protocol] | Type[Protocol]]: Protocol
+    #: DefaultDict[int, ModuleDescriptor[Protocol] | ~typing.Type[Protocol]]: Protocol
     #: index mapping for decoding next layer, c.f.
     #: :meth:`self._decode_next_layer <pcapkit.protocols.transport.transport.Transport._decode_next_layer>`
     #: & :meth:`self._import_next_layer <pcapkit.protocols.protocol.Protocol._import_next_layer>`.