diff --git a/src/test/test-process-util.c b/src/test/test-process-util.c
index 0e5a9d811d7..1a0164e601f 100644
--- a/src/test/test-process-util.c
+++ b/src/test/test-process-util.c
@@ -193,6 +193,8 @@ static void test_get_process_cmdline_harder(void) {
         assert_se(pid == 0);
         assert_se(unshare(CLONE_NEWNS) >= 0);
 
+        assert_se(mount(NULL, "/", NULL, MS_PRIVATE|MS_REC, NULL) >= 0);
+
         fd = mkostemp(path, O_CLOEXEC);
         assert_se(fd >= 0);