diff --git a/include/mount.h b/include/mount.h
index b86114c10..9de9b51f2 100644
--- a/include/mount.h
+++ b/include/mount.h
@@ -11,7 +11,7 @@ extern int collect_mount_info(pid_t pid);
 extern struct fstype *find_fstype_by_name(char *fst);
 
 struct cr_fdset;
-extern int dump_mnt_ns(int pid, struct cr_fdset *);
+extern int dump_mnt_ns(int pid, int ns_id);
 int prepare_mnt_ns(int pid);
 
 extern int pivot_root(const char *new_root, const char *put_old);
diff --git a/mount.c b/mount.c
index 5902dc42c..efec0f882 100644
--- a/mount.c
+++ b/mount.c
@@ -641,37 +641,43 @@ static int dump_one_mountpoint(struct mount_info *pm, int fd)
 	return 0;
 }
 
-int dump_mnt_ns(int ns_pid, struct cr_fdset *fdset)
+int dump_mnt_ns(int ns_pid, int ns_id)
 {
 	struct mount_info *pm;
-	int img_fd;
+	int img_fd, ret = -1;
+
+	img_fd = open_image(CR_FD_MNTS, O_DUMP, ns_id);
+	if (img_fd < 0)
+		return -1;
 
 	pm = parse_mountinfo(ns_pid);
 	if (!pm) {
 		pr_err("Can't parse %d's mountinfo\n", ns_pid);
-		return -1;
+		goto err;
 	}
 
 	if (mnt_build_tree(pm) == NULL)
-		return -1;
+		goto err;
 
 	if (validate_mounts(pm))
-		return -1;
+		goto err;
 
 	pr_info("Dumping mountpoints\n");
 
-	img_fd = fdset_fd(fdset, CR_FD_MNTS);
 	do {
 		struct mount_info *n = pm->next;
 
 		if (dump_one_mountpoint(pm, img_fd))
-			return -1;
+			goto err;
 
 		xfree(pm);
 		pm = n;
 	} while (pm);
 
-	return 0;
+	ret = 0;
+err:
+	close(img_fd);
+	return ret;
 }
 
 /*
diff --git a/namespaces.c b/namespaces.c
index 961d694d8..37593a31b 100644
--- a/namespaces.c
+++ b/namespaces.c
@@ -372,7 +372,7 @@ static int do_dump_namespaces(struct pid *ns_pid, unsigned int ns_flags)
 	}
 	if (ns_flags & CLONE_NEWNS) {
 		pr_info("Dump MNT namespace (mountpoints)\n");
-		ret = dump_mnt_ns(ns_pid->real, fdset);
+		ret = dump_mnt_ns(ns_pid->real, ns_id);
 		if (ret < 0)
 			goto err;
 	}