diff --git a/gattlib-py/gattlib/__init__.py b/gattlib-py/gattlib/__init__.py
index 52d6169..a5eec07 100644
--- a/gattlib-py/gattlib/__init__.py
+++ b/gattlib-py/gattlib/__init__.py
@@ -103,6 +103,16 @@ class GattlibAdvertisementData(Structure):
                 ("data", c_void_p),
                 ("data_length", c_size_t)]
 
+# typedef struct {
+# 	uint16_t manufacturer_id;
+# 	uint8_t* data;
+# 	size_t data_size;
+# } gattlib_manufacturer_data_t;
+class GattlibManufacturerData(Structure):
+    _fields_ = [("manufacturer_id", c_ushort),
+                ("data", c_void_p),
+                ("data_size", c_size_t)]
+
 
 # int gattlib_adapter_open(const char* adapter_name, gattlib_adapter_t** adapter);
 gattlib_adapter_open = gattlib.gattlib_adapter_open
@@ -212,13 +222,13 @@ gattlib_get_rssi_from_mac.argtypes = [c_void_p, c_char_p, POINTER(c_int16)]
 # 		 gattlib_advertisement_data_t **advertisement_data, size_t *advertisement_data_count,
 # 		 gattlib_manufacturer_data_t** manufacturer_data, size_t* manufacturer_data_count)
 gattlib_get_advertisement_data = gattlib.gattlib_get_advertisement_data
-gattlib_get_advertisement_data.argtypes = [c_void_p, POINTER(POINTER(GattlibAdvertisementData)), POINTER(c_size_t), POINTER(c_uint16), POINTER(c_void_p), POINTER(c_size_t)]
+gattlib_get_advertisement_data.argtypes = [c_void_p, POINTER(POINTER(GattlibAdvertisementData)), POINTER(c_size_t), POINTER(POINTER(GattlibManufacturerData)), POINTER(c_size_t)]
 
 # int gattlib_get_advertisement_data_from_mac(gattlib_adapter_t* adapter, const char *mac_address,
 #        gattlib_advertisement_data_t **advertisement_data, size_t *advertisement_data_length,
 #        gattlib_manufacturer_data_t** manufacturer_data, size_t* manufacturer_data_count)
 gattlib_get_advertisement_data_from_mac = gattlib.gattlib_get_advertisement_data_from_mac
-gattlib_get_advertisement_data_from_mac.argtypes = [c_void_p, c_char_p, POINTER(POINTER(GattlibAdvertisementData)), POINTER(c_size_t), POINTER(c_uint16), POINTER(c_void_p), POINTER(c_size_t)]
+gattlib_get_advertisement_data_from_mac.argtypes = [c_void_p, c_char_p, POINTER(POINTER(GattlibAdvertisementData)), POINTER(c_size_t), POINTER(POINTER(GattlibManufacturerData)), POINTER(c_size_t)]
 
 # int gattlib_mainloop_python(PyObject *handler, PyObject *user_data)
 gattlib_mainloop = gattlib.gattlib_mainloop_python
diff --git a/gattlib-py/gattlib/adapter.py b/gattlib-py/gattlib/adapter.py
index 50490fb..3da984a 100644
--- a/gattlib-py/gattlib/adapter.py
+++ b/gattlib-py/gattlib/adapter.py
@@ -9,7 +9,7 @@ from uuid import UUID
 
 from gattlib import *
 from .device import Device
-from .exception import handle_return, AdapterNotOpened
+from .exception import handle_return
 from .uuid import gattlib_uuid_to_int
 
 GATTLIB_DISCOVER_FILTER_USE_UUID = (1 << 0)
@@ -238,18 +238,16 @@ class Adapter:
 
         _advertisement_data = POINTER(GattlibAdvertisementData)()
         _advertisement_data_count = c_size_t(0)
-        _manufacturer_id = c_uint16(0)
-        _manufacturer_data = c_void_p(None)
+        _manufacturer_data = POINTER(GattlibManufacturerData)()
         _manufacturer_data_len = c_size_t(0)
 
         ret = gattlib_get_advertisement_data_from_mac(self._adapter, mac_address,
                                                       byref(_advertisement_data), byref(_advertisement_data_count),
-                                                      byref(_manufacturer_id),
                                                       byref(_manufacturer_data), byref(_manufacturer_data_len))
         handle_return(ret)
 
         advertisement_data = {}
-        manufacturer_data = None
+        manufacturer_data = {}
 
         for i in range(0, _advertisement_data_count.value):
             service_data = _advertisement_data[i]
@@ -264,15 +262,21 @@ class Adapter:
 
             advertisement_data[uuid] = data
 
-        if _manufacturer_data_len.value > 0:
-            pointer_type = POINTER(c_byte * _manufacturer_data_len.value)
-            c_bytearray = cast(_manufacturer_data, pointer_type)
+        for i in range(0, _manufacturer_data_len.value):
+            _manufacturer_data = _manufacturer_data[i]
 
-            manufacturer_data = bytearray(_manufacturer_data_len.value)
-            for i in range(_manufacturer_data_len.value):
-                manufacturer_data[i] = c_bytearray.contents[i] & 0xFF
+            pointer_type = POINTER(c_byte * _manufacturer_data.data_size.value)
+            c_bytearray = cast(_manufacturer_data.data, pointer_type)
+
+            data = bytearray(_manufacturer_data.data_size.value)
+            for j in range(_manufacturer_data.data_size.value):
+                data[j] = c_bytearray.contents[j] & 0xFF
+
+            manufacturer_data[_manufacturer_data.manufacturer_id] = data
+
+            gattlib_free_mem(_manufacturer_data.data)
 
         gattlib_free_mem(_advertisement_data)
         gattlib_free_mem(_manufacturer_data)
 
-        return advertisement_data, _manufacturer_id.value, manufacturer_data
+        return advertisement_data, manufacturer_data
diff --git a/gattlib-py/gattlib/device.py b/gattlib-py/gattlib/device.py
index f061671..161c21e 100644
--- a/gattlib-py/gattlib/device.py
+++ b/gattlib-py/gattlib/device.py
@@ -182,25 +182,22 @@ class Device:
     def get_advertisement_data(self):
         _advertisement_data = POINTER(GattlibAdvertisementData)()
         _advertisement_data_count = c_size_t(0)
-        _manufacturer_id = c_uint16(0)
-        _manufacturer_data = c_void_p(None)
+        _manufacturer_data = POINTER(GattlibManufacturerData)()
         _manufacturer_data_len = c_size_t(0)
 
         if self._connection is None:
             ret = gattlib_get_advertisement_data_from_mac(self._adapter._adapter, self._addr,
                                                           byref(_advertisement_data), byref(_advertisement_data_count),
-                                                          byref(_manufacturer_id),
                                                           byref(_manufacturer_data), byref(_manufacturer_data_len))
         else:
             ret = gattlib_get_advertisement_data(self._connection,
                                                  byref(_advertisement_data), byref(_advertisement_data_count),
-                                                 byref(_manufacturer_id),
                                                  byref(_manufacturer_data), byref(_manufacturer_data_len))
 
         handle_return(ret)
 
         advertisement_data = {}
-        manufacturer_data = None
+        manufacturer_data = {}
 
         for i in range(0, _advertisement_data_count.value):
             service_data = _advertisement_data[i]
@@ -215,18 +212,24 @@ class Device:
 
             advertisement_data[uuid] = data
 
-        if _manufacturer_data_len.value > 0:
-            pointer_type = POINTER(c_byte * _manufacturer_data_len.value)
-            c_bytearray = cast(_manufacturer_data, pointer_type)
+        for i in range(0, _manufacturer_data_len.value):
+            _manufacturer_data = _manufacturer_data[i]
 
-            manufacturer_data = bytearray(_manufacturer_data_len.value)
-            for i in range(_manufacturer_data_len.value):
-                manufacturer_data[i] = c_bytearray.contents[i] & 0xFF
+            pointer_type = POINTER(c_byte * _manufacturer_data.data_size.value)
+            c_bytearray = cast(_manufacturer_data.data, pointer_type)
+
+            data = bytearray(_manufacturer_data.data_size.value)
+            for j in range(_manufacturer_data.data_size.value):
+                data[j] = c_bytearray.contents[j] & 0xFF
+
+            manufacturer_data[_manufacturer_data.manufacturer_id] = data
+
+            gattlib_free_mem(_manufacturer_data.data)
 
         gattlib_free_mem(_advertisement_data)
         gattlib_free_mem(_manufacturer_data)
 
-        return advertisement_data, _manufacturer_id.value, manufacturer_data
+        return advertisement_data, manufacturer_data
 
     @property
     def services(self):