diff --git a/src/dbus_fast/aio/proxy_object.py b/src/dbus_fast/aio/proxy_object.py
index 5a260b09..83c446b8 100644
--- a/src/dbus_fast/aio/proxy_object.py
+++ b/src/dbus_fast/aio/proxy_object.py
@@ -3,9 +3,9 @@
 
 from .. import introspection as intr
 from .._private.util import replace_fds_with_idx, replace_idx_with_fds
-from ..constants import ErrorType
+from ..constants import ErrorType, MessageFlag
 from ..errors import DBusError
-from ..message import Message, MessageFlag
+from ..message import Message
 from ..message_bus import BaseMessageBus
 from ..proxy_object import BaseProxyInterface, BaseProxyObject
 from ..signature import Variant
diff --git a/src/dbus_fast/message.pxd b/src/dbus_fast/message.pxd
index 27067339..21e35c25 100644
--- a/src/dbus_fast/message.pxd
+++ b/src/dbus_fast/message.pxd
@@ -3,21 +3,45 @@
 import cython
 
 
+cdef object ErrorType
+cdef object SignatureTree
+cdef object SignatureType
+cdef object MessageType
+cdef object Variant
+cdef object Marshaller
+
+
+cdef object HEADER_PATH
+cdef object HEADER_INTERFACE
+cdef object HEADER_MEMBER
+cdef object HEADER_ERROR_NAME
+cdef object HEADER_REPLY_SERIAL
+cdef object HEADER_DESTINATION
+cdef object HEADER_SENDER
+cdef object HEADER_SIGNATURE
+cdef object HEADER_UNIX_FDS
+
+
+cdef object LITTLE_ENDIAN
+cdef object PROTOCOL_VERSION
+
+cdef get_signature_tree
+
 cdef class Message:
 
-    cdef public str destination
-    cdef public str path
-    cdef public str interface
-    cdef public str member
+    cdef public object destination
+    cdef public object path
+    cdef public object interface
+    cdef public object member
     cdef public object message_type
     cdef public object flags
-    cdef public str error_name
+    cdef public object error_name
     cdef public unsigned int reply_serial
-    cdef public str sender
-    cdef public list unix_fds
-    cdef public str signature
+    cdef public object sender
+    cdef public object unix_fds
+    cdef public object signature
     cdef public object signature_tree
-    cdef public list body
+    cdef public object body
     cdef public unsigned int serial
 
     cpdef _marshall(self, bint negotiate_unix_fd)
diff --git a/src/dbus_fast/message.py b/src/dbus_fast/message.py
index b123c0db..768973d9 100644
--- a/src/dbus_fast/message.py
+++ b/src/dbus_fast/message.py
@@ -266,33 +266,21 @@ def _marshall(self, negotiate_unix_fd: bool) -> bytearray:
         # Variant is invalid.
 
         if self.path:
-            fields.append([HEADER_PATH, Variant("o", self.path, verify=False)])
+            fields.append([HEADER_PATH, Variant("o", self.path, False)])
         if self.interface:
-            fields.append(
-                [HEADER_INTERFACE, Variant("s", self.interface, verify=False)]
-            )
+            fields.append([HEADER_INTERFACE, Variant("s", self.interface, False)])
         if self.member:
-            fields.append([HEADER_MEMBER, Variant("s", self.member, verify=False)])
+            fields.append([HEADER_MEMBER, Variant("s", self.member, False)])
         if self.error_name:
-            fields.append(
-                [HEADER_ERROR_NAME, Variant("s", self.error_name, verify=False)]
-            )
+            fields.append([HEADER_ERROR_NAME, Variant("s", self.error_name, False)])
         if self.reply_serial:
-            fields.append(
-                [HEADER_REPLY_SERIAL, Variant("u", self.reply_serial, verify=False)]
-            )
+            fields.append([HEADER_REPLY_SERIAL, Variant("u", self.reply_serial, False)])
         if self.destination:
-            fields.append(
-                [HEADER_DESTINATION, Variant("s", self.destination, verify=False)]
-            )
+            fields.append([HEADER_DESTINATION, Variant("s", self.destination, False)])
         if self.signature:
-            fields.append(
-                [HEADER_SIGNATURE, Variant("g", self.signature, verify=False)]
-            )
+            fields.append([HEADER_SIGNATURE, Variant("g", self.signature, False)])
         if self.unix_fds and negotiate_unix_fd:
-            fields.append(
-                [HEADER_UNIX_FDS, Variant("u", len(self.unix_fds), verify=False)]
-            )
+            fields.append([HEADER_UNIX_FDS, Variant("u", len(self.unix_fds), False)])
 
         header_body = [
             LITTLE_ENDIAN,