diff --git a/src/libnm-core-impl/nm-utils.c b/src/libnm-core-impl/nm-utils.c
index 1bc44bb5de..d9956a4dff 100644
--- a/src/libnm-core-impl/nm-utils.c
+++ b/src/libnm-core-impl/nm-utils.c
@@ -4429,6 +4429,10 @@ nm_utils_iface_valid_name(const char *name)
  *
  * In older versions, nm_utils_is_uuid() did not accept %NULL as @str
  * argument. Don't pass %NULL if you run against older versions of libnm.
+ *
+ * Deprecated: 1.32: older versions of NetworkManager had a wrong
+ *   understanding of what makes a valid UUID. This function can thus
+ *   accept some inputs as valid, which in fact are not valid UUIDs.
  */
 gboolean
 nm_utils_is_uuid(const char *str)