diff --git a/vcsserver/exceptions.py b/vcsserver/exceptions.py
--- a/vcsserver/exceptions.py
+++ b/vcsserver/exceptions.py
@@ -37,7 +37,7 @@ def _make_exception(kind, org_exc, *args
     exc = Exception(*args)
     exc._vcs_kind = kind
     exc._org_exc = org_exc
-    exc._org_exc_tb = ''
+    exc._org_exc_tb = getattr(org_exc, '_org_exc_tb', '')
     return exc