diff --git a/src/dbus_fast/_private/unmarshaller.pxd b/src/dbus_fast/_private/unmarshaller.pxd
index 88d6c5dd..3d68d58e 100644
--- a/src/dbus_fast/_private/unmarshaller.pxd
+++ b/src/dbus_fast/_private/unmarshaller.pxd
@@ -12,7 +12,7 @@ cdef unsigned int HEADER_SIGNATURE_SIZE
 cdef class Unmarshaller:
 
     cdef object unix_fds
-    cdef object buf
+    cdef bytearray buf
     cdef object view
     cdef unsigned int pos
     cdef object stream
@@ -30,10 +30,15 @@ cdef class Unmarshaller:
 
     @cython.locals(
         start_len=cython.ulong,
-        missing_bytes=cython.ulong,
+        missing_bytes=cython.ulong
     )
     cpdef read_to_pos(self, unsigned long pos)
 
+    cpdef read_uint32_cast(self, object type_)
+
+    @cython.locals(
+        buf_bytes=cython.bytearray,
+    )
     cpdef read_string_cast(self, type_ = *)
 
     @cython.locals(
@@ -54,6 +59,10 @@ cdef class Unmarshaller:
     )
     cpdef _read_header(self)
 
+    cpdef _read_body(self)
+
+    cpdef unmarshall(self)
+
     @cython.locals(
         beginning_pos=cython.ulong,
         o=cython.ulong,
diff --git a/src/dbus_fast/_private/unmarshaller.py b/src/dbus_fast/_private/unmarshaller.py
index 4a38c596..f8e58d11 100644
--- a/src/dbus_fast/_private/unmarshaller.py
+++ b/src/dbus_fast/_private/unmarshaller.py
@@ -218,6 +218,10 @@ def read_to_pos(self, pos) -> None:
         if len(data) + start_len != pos:
             raise MarshallerStreamEndError()
 
+    def read_uint32_cast(self, signature: SignatureType) -> Any:
+        self.pos += UINT32_SIZE + (-self.pos & (UINT32_SIZE - 1))  # align
+        return self.view[self.pos - UINT32_SIZE : self.pos].cast(UINT32_CAST)[0]
+
     def read_boolean(self, type_=None) -> bool:
         return bool(self.readers[UINT32_SIGNATURE.token](self, UINT32_SIGNATURE))
 
@@ -228,8 +232,7 @@ def read_string_cast(self, type_=None) -> str:
         # read terminating '\0' byte as well (str_length + 1)
         start_pos = self.pos - UINT32_SIZE
         self.pos += self.view[start_pos : self.pos].cast(UINT32_CAST)[0] + 1
-        end_pos = self.pos - 1
-        return self.buf[str_start:end_pos].decode()
+        return self.buf[str_start : self.pos - 1].decode()
 
     def read_string_unpack(self, type_=None) -> str:
         """Read a string using unpack."""
@@ -397,12 +400,12 @@ def unmarshall(self):
         to be resumed when more data comes in over the wire.
         """
         try:
-            if not self.message_type:
+            if not self.msg_len:
                 self._read_header()
             self._read_body()
         except MarshallerStreamEndError:
             return None
-        return self.message
+        return self._message
 
     _complex_parsers_unpack: Dict[
         str, Callable[["Unmarshaller", SignatureType], Any]
@@ -426,6 +429,8 @@ def unmarshall(self):
         "(": read_struct,
         "{": read_dict_entry,
         "v": read_variant,
+        "h": read_uint32_cast,
+        UINT32_DBUS_TYPE: read_uint32_cast,
     }
 
     _ctype_by_endian: Dict[