diff --git a/src/libsystemd/sd-netlink/sd-netlink.c b/src/libsystemd/sd-netlink/sd-netlink.c
index 1202fe10a5..ec1035fdd1 100644
--- a/src/libsystemd/sd-netlink/sd-netlink.c
+++ b/src/libsystemd/sd-netlink/sd-netlink.c
@@ -593,7 +593,8 @@ int sd_netlink_read(
                                 return r;
 
                         if (type == NLMSG_DONE) {
-                                *ret = NULL;
+                                if (ret)
+                                        *ret = NULL;
                                 return 0;
                         }