diff --git a/tests/Promise.py b/tests/Promise.py
index 51aab6b6..ca8e2813 100644
--- a/tests/Promise.py
+++ b/tests/Promise.py
@@ -7,6 +7,7 @@ from enum import Enum
 class PromiseResultType(Enum):
     Result = 1
     Exception = 2
+    Traceback = 3
 
 
 class Promise(object):
@@ -24,7 +25,14 @@ class Promise(object):
         res = self._queue.get(timeout=timeout)
         if res[0] == PromiseResultType.Result:
             return res[1]
-        raise res[1]
+        elif res[0] == PromiseResultType.Exception:
+            raise res[1]
+        else:
+            et, ev, tb = res[1]
+            raise et, ev, tb
     
-    def set_exception(self, val):
-        self._queue.put((PromiseResultType.Exception, val))
+    def set_exception(self, valueOrType, val=None, tb=None):
+        if val is None:
+            self._queue.put((PromiseResultType.Exception, val))
+        else:
+            self._queue.put((PromiseResultType.Traceback, (valueOrType, val, tb)))