diff --git a/src/libsystemd/sd-netlink/netlink-message.c b/src/libsystemd/sd-netlink/netlink-message.c
index 874fffe9d9..182c74ed3d 100644
--- a/src/libsystemd/sd-netlink/netlink-message.c
+++ b/src/libsystemd/sd-netlink/netlink-message.c
@@ -147,7 +147,7 @@ sd_netlink_message *sd_netlink_message_unref(sd_netlink_message *m) {
 
 int sd_netlink_message_get_type(sd_netlink_message *m, uint16_t *type) {
         assert_return(m, -EINVAL);
-        assert_return(type, -EINVAL);
+        assert_return(type != 0, -EINVAL);
 
         *type = m->hdr->nlmsg_type;
 
@@ -156,7 +156,7 @@ int sd_netlink_message_get_type(sd_netlink_message *m, uint16_t *type) {
 
 int sd_netlink_message_set_flags(sd_netlink_message *m, uint16_t flags) {
         assert_return(m, -EINVAL);
-        assert_return(flags, -EINVAL);
+        assert_return(flags != 0, -EINVAL);
 
         m->hdr->nlmsg_flags = flags;