diff --git a/NEWS b/NEWS
index 2430fa115c..da3ea1342a 100644
--- a/NEWS
+++ b/NEWS
@@ -379,6 +379,10 @@ CHANGES WITH 240 in spe:
           interface names even as systemd/udev are updated and the naming logic
           is improved.
 
+        * sd-id128.h learnt two new auxiliary helpers: sd_id128_is_allf() and
+          SD_ID128_ALLF to test if a 128bit ID is set to all 0xFF bytes, and to
+          initialize one to all 0xFF.
+
         Contributions from: afg, Alan Jenkins, Aleksei Timofeyev, Alexander
         Filippov, Alexander Kurtz, Alexey Bogdanenko, Andreas Henriksson,
         Andrew Jorgensen, Anita Zhang, apnix-uk, Arkan49, Arseny Maslennikov,
diff --git a/src/systemd/sd-id128.h b/src/systemd/sd-id128.h
index 59f375bef5..f4c05a3683 100644
--- a/src/systemd/sd-id128.h
+++ b/src/systemd/sd-id128.h
@@ -110,7 +110,12 @@ _sd_pure_ static __inline__ int sd_id128_is_null(sd_id128_t a) {
         return a.qwords[0] == 0 && a.qwords[1] == 0;
 }
 
+_sd_pure_ static __inline__ int sd_id128_is_allf(sd_id128_t a) {
+        return a.qwords[0] == UINT64_C(0xFFFFFFFFFFFFFFFF) && a.qwords[1] == UINT64_C(0xFFFFFFFFFFFFFFFF);
+}
+
 #define SD_ID128_NULL ((const sd_id128_t) { .qwords = { 0, 0 }})
+#define SD_ID128_ALLF ((const sd_id128_t) { .qwords = { UINT64_C(0xFFFFFFFFFFFFFFFF), UINT64_C(0xFFFFFFFFFFFFFFFF) }})
 
 _SD_END_DECLARATIONS;