diff --git a/SoftLayer/transports.py b/SoftLayer/transports.py
index 02cd7a214..5722e1867 100644
--- a/SoftLayer/transports.py
+++ b/SoftLayer/transports.py
@@ -564,7 +564,8 @@ def _format_object_mask(objectmask):
     objectmask = objectmask.strip()
 
     if (not objectmask.startswith('mask') and
-            not objectmask.startswith('[')):
+            not objectmask.startswith('[') and
+            not objectmask.startswith('filteredMask')):
         objectmask = "mask[%s]" % objectmask
     return objectmask
 
diff --git a/tests/transport_tests.py b/tests/transport_tests.py
index 6e6c793fd..a2e500bd8 100644
--- a/tests/transport_tests.py
+++ b/tests/transport_tests.py
@@ -228,6 +228,22 @@ def test_mask_call_v2(self, request):
             "<value><string>mask[something[nested]]</string></value>",
             kwargs['data'])
 
+    @mock.patch('SoftLayer.transports.requests.Session.request')
+    def test_mask_call_filteredMask(self, request):
+        request.return_value = self.response
+
+        req = transports.Request()
+        req.endpoint = "http://something.com"
+        req.service = "SoftLayer_Service"
+        req.method = "getObject"
+        req.mask = "filteredMask[something[nested]]"
+        self.transport(req)
+
+        args, kwargs = request.call_args
+        self.assertIn(
+            "<value><string>filteredMask[something[nested]]</string></value>",
+            kwargs['data'])
+
     @mock.patch('SoftLayer.transports.requests.Session.request')
     def test_mask_call_v2_dot(self, request):
         request.return_value = self.response