diff --git a/mssql/base.py b/mssql/base.py
index 8adc94b..6896bd4 100644
--- a/mssql/base.py
+++ b/mssql/base.py
@@ -126,7 +126,7 @@ class DatabaseWrapper(BaseDatabaseWrapper):
         'SmallIntegerField': 'smallint',
         'TextField': 'nvarchar(max)',
         'TimeField': 'time',
-        'UUIDField': 'uniqueidentifier',
+        'UUIDField': 'char(32)',
     }
     data_types_suffix = {
         'AutoField': 'IDENTITY (1, 1)',
@@ -432,9 +432,6 @@ def init_connection_state(self):
         if (options.get('return_rows_bulk_insert', False)):
             self.features_class.can_return_rows_from_bulk_insert = True
 
-        if (options.get('has_native_uuid_field', True)):
-            Database.native_uuid = True
-            
         val = self.get_system_datetime
         if isinstance(val, str):
             raise ImproperlyConfigured(
diff --git a/mssql/features.py b/mssql/features.py
index b2480f5..d63fcc4 100644
--- a/mssql/features.py
+++ b/mssql/features.py
@@ -22,7 +22,7 @@ class DatabaseFeatures(BaseDatabaseFeatures):
     has_json_object_function = False
     has_json_operators = False
     has_native_json_field = False
-    has_native_uuid_field = True
+    has_native_uuid_field = False
     has_real_datatype = True
     has_select_for_update = True
     has_select_for_update_nowait = True
diff --git a/mssql/operations.py b/mssql/operations.py
index 6a00c83..b83305a 100644
--- a/mssql/operations.py
+++ b/mssql/operations.py
@@ -129,7 +129,7 @@ def convert_floatfield_value(self, value, expression, connection):
 
     def convert_uuidfield_value(self, value, expression, connection):
         if value is not None:
-            value = uuid.UUID(str(value))
+            value = uuid.UUID(value)
         return value
 
     def convert_booleanfield_value(self, value, expression, connection):