diff --git a/test/zdtm.py b/test/zdtm.py
index 019b49bfd..c2d3ebcec 100755
--- a/test/zdtm.py
+++ b/test/zdtm.py
@@ -174,7 +174,7 @@ class ns_flavor:
 		self.__mknod("rtc")
 
 	def init(self, l_bins, x_bins):
-		subprocess.check_call(["mount", "--make-private", "--bind", ".", self.root])
+		subprocess.check_call(["mount", "--make-slave", "--bind", ".", self.root])
 		self.root_mounted = True
 
 		if not os.access(self.root + "/.constructed", os.F_OK):