diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 02b5c306..12d89b5b 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -19,7 +19,6 @@ repos:
       - id: debug-statements
       - id: check-builtin-literals
       - id: check-case-conflict
-      - id: check-docstring-first
       - id: check-json
       - id: check-toml
       - id: check-xml
diff --git a/bench/unmarshall_passive.py b/bench/unmarshall_passive.py
index 243d3d91..c563bdbc 100644
--- a/bench/unmarshall_passive.py
+++ b/bench/unmarshall_passive.py
@@ -21,6 +21,7 @@
 def unmarhsall_bluez_rssi_message():
     stream.seek(0)
     unmarshaller.unmarshall()
+    unmarshaller.unmarshall()
 
 
 count = 3000000
diff --git a/src/dbus_fast/_private/unmarshaller.pxd b/src/dbus_fast/_private/unmarshaller.pxd
index f86b1431..76610f91 100644
--- a/src/dbus_fast/_private/unmarshaller.pxd
+++ b/src/dbus_fast/_private/unmarshaller.pxd
@@ -112,16 +112,18 @@ cdef class Unmarshaller:
     cdef unsigned int _body_len
     cdef unsigned int _serial
     cdef unsigned int _header_len
-    cdef object _message_type
-    cdef object _flag
+    cdef unsigned int _message_type
+    cdef unsigned int _flag
     cdef unsigned int _msg_len
     cdef unsigned int _is_native
     cdef object _uint32_unpack
     cdef object _int16_unpack
     cdef object _uint16_unpack
     cdef object _stream_reader
+    cdef object _sock_reader
     cdef bint _negotiate_unix_fd
     cdef bint _read_complete
+    cdef unsigned int _endian
 
     cdef _next_message(self)
 
diff --git a/src/dbus_fast/_private/unmarshaller.py b/src/dbus_fast/_private/unmarshaller.py
index fcf9ba9c..48b7239c 100644
--- a/src/dbus_fast/_private/unmarshaller.py
+++ b/src/dbus_fast/_private/unmarshaller.py
@@ -202,8 +202,10 @@ class Unmarshaller:
         "_uint16_unpack",
         "_is_native",
         "_stream_reader",
+        "_sock_reader",
         "_negotiate_unix_fd",
         "_read_complete",
+        "_endian",
     )
 
     def __init__(
@@ -236,6 +238,11 @@ def __init__(
             if isinstance(stream, io.BufferedRWPair) and hasattr(stream, "reader"):
                 self._stream_reader = stream.reader.read  # type: ignore[attr-defined]
             self._stream_reader = stream.read
+        elif self._negotiate_unix_fd:
+            self._sock_reader = self._sock.recvmsg
+        else:
+            self._sock_reader = self._sock.recv
+        self._endian = 0
 
     def _next_message(self) -> None:
         """Reset the unmarshaller to its initial state.
@@ -280,7 +287,7 @@ def _read_sock_with_fds(self, pos: _int, missing_bytes: _int) -> None:
         # This will raise BlockingIOError if there is no data to read
         # which we store in the MARSHALL_STREAM_END_ERROR object
         try:
-            recv = self._sock.recvmsg(missing_bytes, UNIX_FDS_CMSG_LENGTH)  # type: ignore[union-attr]
+            recv = self._sock_reader(missing_bytes, UNIX_FDS_CMSG_LENGTH)  # type: ignore[union-attr]
         except OSError as e:
             errno = e.errno
             if errno == EAGAIN or errno == EWOULDBLOCK:
@@ -311,7 +318,7 @@ def _read_sock_without_fds(self, pos: _int) -> None:
         # which we store in the MARSHALL_STREAM_END_ERROR object
         while True:
             try:
-                data = self._sock.recv(DEFAULT_BUFFER_SIZE)  # type: ignore[union-attr]
+                data = self._sock_reader(DEFAULT_BUFFER_SIZE)  # type: ignore[union-attr]
             except OSError as e:
                 errno = e.errno
                 if errno == EAGAIN or errno == EWOULDBLOCK:
@@ -650,7 +657,9 @@ def _read_header(self) -> None:
         self._msg_len = (
             self._header_len + (-self._header_len & 7) + self._body_len
         )  # align 8
-        self._readers = self._readers_by_type[endian]
+        if self._endian != endian:
+            self._readers = self._readers_by_type[endian]
+            self._endian = endian
 
     def _read_body(self) -> None:
         """Read the body of the message."""
diff --git a/src/dbus_fast/signature.py b/src/dbus_fast/signature.py
index 6eb1df8d..f852f00e 100644
--- a/src/dbus_fast/signature.py
+++ b/src/dbus_fast/signature.py
@@ -435,14 +435,12 @@ def __repr__(self) -> str:
         )
 
 
-@lru_cache(maxsize=None)
-def get_signature_tree(signature: str) -> SignatureTree:
-    """Get a signature tree for the given signature.
+get_signature_tree = lru_cache(maxsize=None)(SignatureTree)
+"""Get a signature tree for the given signature.
 
-    :param signature: The signature to get a tree for.
-    :type signature: str
+:param signature: The signature to get a tree for.
+:type signature: str
 
-    :returns: The signature tree for the given signature.
-    :rtype: :class:`SignatureTree`
-    """
-    return SignatureTree(signature)
+:returns: The signature tree for the given signature.
+:rtype: :class:`SignatureTree`
+"""