diff --git a/src/libsystemd-network/dhcp6-option.c b/src/libsystemd-network/dhcp6-option.c
index 321d0d21df..a4278528ab 100644
--- a/src/libsystemd-network/dhcp6-option.c
+++ b/src/libsystemd-network/dhcp6-option.c
@@ -86,7 +86,10 @@ int dhcp6_option_append_ia(uint8_t **buf, size_t *buflen, const DHCP6IA *ia) {
         DHCP6Address *addr;
         int r;
 
-        assert_return(buf && *buf && buflen && ia, -EINVAL);
+        assert_return(buf, -EINVAL);
+        assert_return(*buf, -EINVAL);
+        assert_return(buflen, -EINVAL);
+        assert_return(ia, -EINVAL);
 
         switch (ia->type) {
         case SD_DHCP6_OPTION_IA_NA: