diff --git a/gramps/gen/utils/unknown.py b/gramps/gen/utils/unknown.py
index b565e535d..33872c7b9 100644
--- a/gramps/gen/utils/unknown.py
+++ b/gramps/gen/utils/unknown.py
@@ -32,6 +32,7 @@ Make an 'Unknown' primary object
 #
 #-------------------------------------------------------------------------
 import time
+import os
 
 #-------------------------------------------------------------------------
 #