diff --git a/src/platform/tests/test-common.c b/src/platform/tests/test-common.c
index b1947a6d11..51d2a5e234 100644
--- a/src/platform/tests/test-common.c
+++ b/src/platform/tests/test-common.c
@@ -1554,6 +1554,10 @@ unshare_user (void)
 	uid_t uid = geteuid ();
 	gid_t gid = getegid ();
 
+	/* Don't try to set up the namespaces if we're in a container. */
+	if (!nmtstp_is_sysfs_writable ())
+		return FALSE;
+
 	/* Already a root? */
 	if (gid == 0 && uid == 0)
 		return TRUE;