diff --git a/test/zlib.py b/test/zlib.py
index c2ce0686e..109e9d7b4 100755
--- a/test/zlib.py
+++ b/test/zlib.py
@@ -8,7 +8,7 @@
 import BoostBuild
 import MockToolset
 
-t = BoostBuild.Tester(arguments=['toolset=mock'], pass_toolset=0)
+t = BoostBuild.Tester(arguments=['toolset=mock', '--ignore-site-config', '--user-config='], pass_toolset=0)
 
 MockToolset.create(t)