diff --git a/samples/MultipleReadPropertyThreaded.py b/samples/MultipleReadPropertyThreaded.py
index a659da23..6370e0fe 100755
--- a/samples/MultipleReadPropertyThreaded.py
+++ b/samples/MultipleReadPropertyThreaded.py
@@ -20,7 +20,7 @@
 from bacpypes.object import get_datatype
 
 from bacpypes.apdu import ReadPropertyRequest
-from bacpypes.primitivedata import Unsigned
+from bacpypes.primitivedata import Unsigned, ObjectIdentifier
 from bacpypes.constructeddata import Array
 
 from bacpypes.app import BIPSimpleApplication
@@ -64,7 +64,7 @@ def run(self):
         for addr, obj_id, prop_id in self.point_queue:
             # build a request
             request = ReadPropertyRequest(
-                objectIdentifier=ObjectIdentifer(obj_id).value,
+                objectIdentifier=ObjectIdentifier(obj_id).value,
                 propertyIdentifier=prop_id,
                 )
             request.pduDestination = Address(addr)