diff --git a/CHANGELOG.md b/CHANGELOG.md
index 64a317f..ff0ac90 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,8 @@
+### v0.8.11 (2018-03-04)
+
+  * Change IOTileDeviceSlug back to accepting 64bits by default, but add a new allow_64bits option to be turned off
+  if required to enforce 48bit checks
+
 ### v0.8.10 (2018-03-02)
 
   * Fix bug and missing tests in IOTileFleetSlug
diff --git a/iotile_cloud/utils/gid.py b/iotile_cloud/utils/gid.py
index 731c245..9a979a2 100644
--- a/iotile_cloud/utils/gid.py
+++ b/iotile_cloud/utils/gid.py
@@ -100,13 +100,17 @@ def __init__(self, id):
 class IOTileDeviceSlug(IOTileCloudSlug):
     """Formatted Global Device ID: d--0000-0000-0000-0001"""
 
-    def __init__(self, id):
+    def __init__(self, id, allow_64bits=True):
+        # For backwards compatibility, allow 64 bit IDs if required
+        # Meaning that the device may in fact be a data block
+        hex_count = 16 if allow_64bits else 12
+
         if isinstance(id, IOTileDeviceSlug):
             self._slug = id._slug
             return
 
         if isinstance(id, int):
-            if id <= 0 or id >= pow(16, 12):
+            if id <= 0 or id >= pow(16, hex_count):
                 raise ValueError('IOTileDeviceSlug: UUID should be greater than zero and less than 16^12')
             did = int2did(id)
         else:
@@ -122,9 +126,8 @@ def __init__(self, id):
 
             # Convert to int and back to get rid of anything above 48 bits
             id = gid2int(did)
-            if id <= 0 or id >= pow(16, 12):
+            if id <= 0 or id >= pow(16, hex_count):
                 raise ValueError('IOTileDeviceSlug: UUID should be greater than zero and less than 16^12')
-            did = int2did(id)
 
         self.set_from_single_id_slug('d', 4, did)
 
@@ -301,7 +304,8 @@ def from_parts(self, project, device, variable):
         if not isinstance(project, IOTileProjectSlug):
             project = IOTileProjectSlug(project)
         if not isinstance(device, IOTileDeviceSlug):
-            device = IOTileDeviceSlug(device)
+            # Allow 64bits to handle blocks
+            device = IOTileDeviceSlug(device, allow_64bits=True)
         if not isinstance(variable, IOTileVariableSlug):
             variable = IOTileVariableSlug(variable)
         self._slug = gid_join(['s', project.formatted_id(), device.formatted_id(), variable.formatted_local_id()])
@@ -310,7 +314,7 @@ def get_parts(self):
         parts = gid_split(self._slug)
         assert(len(parts) == 4)
         project = IOTileProjectSlug(parts[1])
-        device = IOTileDeviceSlug(parts[2])
+        device = IOTileDeviceSlug(parts[2], allow_64bits=True)
         variable = IOTileVariableSlug(parts[3], project)
         result = {
             'project': str(project),
diff --git a/tests/test_gid.py b/tests/test_gid.py
index 28eb3ff..9e88294 100644
--- a/tests/test_gid.py
+++ b/tests/test_gid.py
@@ -49,6 +49,9 @@ def test_device_slug(self):
         id = IOTileDeviceSlug('d--1234')
         self.assertEqual(str(id), 'd--0000-0000-0000-1234')
 
+        id = IOTileDeviceSlug('d--1234-0000-0000-0001', allow_64bits=True)
+        self.assertEqual(str(id), 'd--1234-0000-0000-0001')
+
         id = IOTileDeviceSlug('0005')
         self.assertEqual(str(id), 'd--0000-0000-0000-0005')
         self.assertEqual(id.formatted_id(), '0000-0000-0000-0005')
@@ -56,10 +59,11 @@ def test_device_slug(self):
         self.assertRaises(ValueError, IOTileDeviceSlug, 'string')
         self.assertRaises(ValueError, IOTileDeviceSlug, 'x--0000-0000-0000-0001')
         self.assertRaises(ValueError, IOTileDeviceSlug, '0000-0000-0000-0000')
-        self.assertRaises(ValueError, IOTileDeviceSlug, 'd--1234-0000-0000-0001') # > 48bts
+        self.assertRaises(ValueError, IOTileDeviceSlug, 'd--1234-0000-0000-0001', False) # > 48bts
         self.assertRaises(ValueError, IOTileDeviceSlug, -5)
         self.assertRaises(ValueError, IOTileDeviceSlug, 0)
-        self.assertRaises(ValueError, IOTileDeviceSlug, pow(16,12))
+        self.assertRaises(ValueError, IOTileDeviceSlug, pow(16,16))
+        self.assertRaises(ValueError, IOTileDeviceSlug, pow(16,12), False)
 
     def test_block_slug(self):
         id = IOTileBlockSlug(5)
diff --git a/version.py b/version.py
index c0bfba8..742dbb9 100644
--- a/version.py
+++ b/version.py
@@ -1 +1 @@
-version = '0.8.10'
+version = '0.8.11'