Index: vncdotool-1.0.0/tests/unit/helpers.py
===================================================================
--- vncdotool-1.0.0.orig/tests/unit/helpers.py
+++ vncdotool-1.0.0/tests/unit/helpers.py
@@ -1,5 +1,7 @@
 import sys
-from unittest.mock import Mock, _importer
+import pkgutil
+from unittest.mock import Mock
+
 from functools import wraps
 
 class _isolate(object):
@@ -102,7 +104,7 @@ def isolate(target, excludes=None):
 
     ``isolate`` borrows heavily from DingusTestCase.
     """
-    target = _importer(target)
+    target = pkgutil.resolve_name(target)
     return _isolate(target, excludes)