diff --git a/netns b/netns
index b762ace..d4d841d 100755
--- a/netns
+++ b/netns
@@ -66,7 +66,7 @@ _setup_mountns() {
     fi
 
     touch "$mountns_path"
-    unshare --mount="$mountns_path" \
+    unshare --mount="$mountns_path" --propagation=slave \
         mount -t overlay overlay -o "upperdir=$etc_path,lowerdir=/etc/,workdir=$workdir_path" /etc/
 }