diff --git a/src/systemd/src/libsystemd-network/dhcp6-option.c b/src/systemd/src/libsystemd-network/dhcp6-option.c
index e462b7083d..ff1cbf13d8 100644
--- a/src/systemd/src/libsystemd-network/dhcp6-option.c
+++ b/src/systemd/src/libsystemd-network/dhcp6-option.c
@@ -566,7 +566,7 @@ int dhcp6_option_parse_domainname(const uint8_t *optval, uint16_t optlen, char *
                                 /* Literal label */
                                 label = (const char *)&optval[pos];
                                 pos += c;
-                                if (pos > optlen)
+                                if (pos >= optlen)
                                         return -EMSGSIZE;
 
                                 if (!GREEDY_REALLOC(ret, allocated, n + !first + DNS_LABEL_ESCAPED_MAX)) {