diff --git a/src/dbus_fast/_private/unmarshaller.pxd b/src/dbus_fast/_private/unmarshaller.pxd
index 1147666b..f577836c 100644
--- a/src/dbus_fast/_private/unmarshaller.pxd
+++ b/src/dbus_fast/_private/unmarshaller.pxd
@@ -137,20 +137,20 @@ cdef class Unmarshaller:
         recv=cython.tuple,
         errno=cython.uint
     )
-    cdef _read_sock_with_fds(self, unsigned int pos, unsigned int missing_bytes)
+    cdef void _read_sock_with_fds(self, unsigned int pos, unsigned int missing_bytes)
 
     @cython.locals(
         data=cython.bytes,
         errno=cython.uint
     )
-    cdef _read_sock_without_fds(self, unsigned int pos)
+    cdef void _read_sock_without_fds(self, unsigned int pos)
 
     @cython.locals(
         data=cython.bytes
     )
-    cdef _read_stream(self, unsigned int pos, unsigned int missing_bytes)
+    cdef void _read_stream(self, unsigned int pos, unsigned int missing_bytes)
 
-    cdef _read_to_pos(self, unsigned int pos)
+    cdef void _read_to_pos(self, unsigned int pos)
 
     cpdef read_boolean(self, SignatureType type_)
 
diff --git a/src/dbus_fast/_private/unmarshaller.py b/src/dbus_fast/_private/unmarshaller.py
index 48bbf302..833ef128 100644
--- a/src/dbus_fast/_private/unmarshaller.py
+++ b/src/dbus_fast/_private/unmarshaller.py
@@ -300,7 +300,7 @@ def _read_sock_with_fds(self, pos: _int, missing_bytes: _int) -> None:
                 self._unix_fds.extend(
                     ARRAY("i", data[: len(data) - (len(data) % MAX_UNIX_FDS_SIZE)])
                 )
-        if msg == b"":
+        if not msg:
             raise EOFError()
         self._buf += msg
         if len(self._buf) < pos:
@@ -322,7 +322,7 @@ def _read_sock_without_fds(self, pos: _int) -> None:
                 if errno == EAGAIN or errno == EWOULDBLOCK:
                     raise MARSHALL_STREAM_END_ERROR
                 raise
-            if data == b"":
+            if not data:
                 raise EOFError()
             self._buf += data
             if len(self._buf) >= pos:
@@ -333,7 +333,7 @@ def _read_stream(self, pos: _int, missing_bytes: _int) -> bytes:
         data = self._stream_reader(missing_bytes)  # type: ignore[misc]
         if data is None:
             raise MARSHALL_STREAM_END_ERROR
-        if data == b"":
+        if not data:
             raise EOFError()
         self._buf += data
         if len(self._buf) < pos: