diff --git a/bench/unmarshall_servicedata.py b/bench/unmarshall_servicedata.py
new file mode 100644
index 00000000..16eb6d7d
--- /dev/null
+++ b/bench/unmarshall_servicedata.py
@@ -0,0 +1,32 @@
+import io
+import timeit
+
+from dbus_fast._private.unmarshaller import Unmarshaller
+
+#  cythonize -X language_level=3 -a -i  src/dbus_fast/_private/unmarshaller.py
+
+
+bluez_properties_changed_message = (
+    b"l\4\1\1\334\0\0\0@\236.\0\226\0\0\0\1\1o\0%\0\0\0/org/bluez/hci0/dev_58_2D_34_60_DA_1F"
+    b"\0\0\0\2\1s\0\37\0\0\0org.freedesktop.DBus.Properties\0\3\1s\0\21\0\0\0PropertiesChanged"
+    b"\0\0\0\0\0\0\0\10\1g\0\10sa{sv}as\0\0\0\7\1s\0\5\0\0\0:1.12\0\0\0\21\0\0\0org.bluez.Devi"
+    b"ce1\0\0\0\270\0\0\0\0\0\0\0\4\0\0\0RSSI\0\1n\0\301\377\0\0\v\0\0\0ServiceData\0\5a{sv}"
+    b"\0\0\210\0\0\0\0\0\0\0$\0\0\0000000fdcd-0000-1000-8000-00805f9b34fb\0\2ay\0\0\0\0\24\0"
+    b"\0\0\10\22\37\332`4-X\2\1U\17\1\315\t\4\5\0\0\0$\0\0\0000000fe95-0000-1000-8000-00805f"
+    b"9b34fb\0\2ay\0\0\0\0\f\0\0\0000X\203\n\2\37\332`4-X\10\0\0\0\0"
+)
+
+
+stream = io.BytesIO(bluez_properties_changed_message)
+unmarshaller = Unmarshaller(stream)
+
+
+def unmarshall_properties_changed_message():
+    stream.seek(0)
+    unmarshaller.reset()
+    unmarshaller.unmarshall()
+
+
+count = 3000000
+time = timeit.Timer(unmarshall_properties_changed_message).timeit(count)
+print(f"Unmarshalling {count} bluetooth PropertiesChanged messages took {time} seconds")
diff --git a/src/dbus_fast/_private/unmarshaller.pxd b/src/dbus_fast/_private/unmarshaller.pxd
index 93dc5fe7..e5572c99 100644
--- a/src/dbus_fast/_private/unmarshaller.pxd
+++ b/src/dbus_fast/_private/unmarshaller.pxd
@@ -113,7 +113,7 @@ cdef class Unmarshaller:
 
     cpdef read_boolean(self, object type_)
 
-    cdef bint _read_boolean(self)
+    cdef _read_boolean(self)
 
     cpdef read_uint32_unpack(self, object type_)
 
diff --git a/tests/test_marshaller.py b/tests/test_marshaller.py
index 58fa3111..1cf106c2 100644
--- a/tests/test_marshaller.py
+++ b/tests/test_marshaller.py
@@ -364,6 +364,75 @@ def test_unmarshall_bluez_interfaces_removed_message():
     ]
 
 
+def test_unmarshall_bluez_properties_changed_with_service_data():
+    bluez_properties_changed_message = (
+        b"l\4\1\1\334\0\0\0@\236.\0\226\0\0\0\1\1o\0%\0\0\0/org/bluez/hci0/dev_58_2D_34_60_DA_1F"
+        b"\0\0\0\2\1s\0\37\0\0\0org.freedesktop.DBus.Properties\0\3\1s\0\21\0\0\0PropertiesChanged"
+        b"\0\0\0\0\0\0\0\10\1g\0\10sa{sv}as\0\0\0\7\1s\0\5\0\0\0:1.12\0\0\0\21\0\0\0org.bluez.Devi"
+        b"ce1\0\0\0\270\0\0\0\0\0\0\0\4\0\0\0RSSI\0\1n\0\301\377\0\0\v\0\0\0ServiceData\0\5a{sv}"
+        b"\0\0\210\0\0\0\0\0\0\0$\0\0\0000000fdcd-0000-1000-8000-00805f9b34fb\0\2ay\0\0\0\0\24\0"
+        b"\0\0\10\22\37\332`4-X\2\1U\17\1\315\t\4\5\0\0\0$\0\0\0000000fe95-0000-1000-8000-00805f"
+        b"9b34fb\0\2ay\0\0\0\0\f\0\0\0000X\203\n\2\37\332`4-X\10\0\0\0\0"
+    )
+
+    stream = io.BytesIO(bluez_properties_changed_message)
+    unmarshaller = Unmarshaller(stream)
+    assert unmarshaller.unmarshall()
+    message = unmarshaller.message
+    assert message is not None
+    assert message is not None
+    assert message.body == [
+        "org.bluez.Device1",
+        {
+            "RSSI": Variant("n", -63),
+            "ServiceData": Variant(
+                "a{sv}",
+                {
+                    "0000fdcd-0000-1000-8000-00805f9b34fb": Variant(
+                        "ay",
+                        bytearray(
+                            b"\x08\x12\x1f\xda`4-X\x02\x01U\x0f\x01\xcd\t\x04\x05\x00\x00\x00"
+                        ),
+                    ),
+                    "0000fe95-0000-1000-8000-00805f9b34fb": Variant(
+                        "ay", bytearray(b"0X\x83\n\x02\x1f\xda`4-X\x08")
+                    ),
+                },
+            ),
+        },
+        [],
+    ]
+    assert message.sender == ":1.12"
+    assert message.path == "/org/bluez/hci0/dev_58_2D_34_60_DA_1F"
+    assert message.interface == "org.freedesktop.DBus.Properties"
+    assert message.member == "PropertiesChanged"
+    assert message.signature == "sa{sv}as"
+    assert message.message_type == MessageType.SIGNAL
+    assert message.flags == MessageFlag.NO_REPLY_EXPECTED
+    assert message.serial == 3055168
+    assert message.destination is None
+    unpacked = unpack_variants(message.body)
+    assert unpacked == [
+        "org.bluez.Device1",
+        {
+            "RSSI": -63,
+            "ServiceData": {
+                "0000fdcd-0000-1000-8000-00805f9b34fb": bytearray(
+                    b"\x08\x12\x1f\xda"
+                    b"`4-X"
+                    b"\x02\x01U\x0f"
+                    b"\x01\xcd\t\x04"
+                    b"\x05\x00\x00\x00"
+                ),
+                "0000fe95-0000-1000-8000-00805f9b34fb": bytearray(
+                    b"0X\x83\n" b"\x02\x1f\xda`" b"4-X\x08"
+                ),
+            },
+        },
+        [],
+    ]
+
+
 def test_ay_buffer():
     body = [bytes(10000)]
     msg = Message(path="/test", member="test", signature="ay", body=body)