diff --git a/NEWS b/NEWS
index 0fb8ed9a1a..2d32bd08b4 100644
--- a/NEWS
+++ b/NEWS
@@ -11,6 +11,16 @@ CHANGES WITH 261 in spe:
           has been repurposed as a standalone switch (without argument) to select
           the user service manager scope, matching --system.
 
+        * Several configuration fields in the io.systemd.Unit varlink interface
+          that were previously exposed as plain strings have been converted to
+          proper enum types. This adds type safety and IDL-level validation.
+          The output wire format now uses underscores instead of dashes and
+          plus signs in enum values (e.g. "tty-force" becomes "tty_force",
+          "kmsg+console" becomes "kmsg_console"). The previous use of plain
+          strings for these well-defined enumerations is considered a bug.
+          Affected enum types: ExecInputType, ExecOutputType, ProtectHome,
+          CGroupController, CollectMode, EmergencyAction, JobMode.
+
         * It was discovered that systemd-stub does not measure all the events
           it measures to the TPM to the hardware CC registers (e.g. Intel TDX
           RTMRs) using EFI_CC_MEASUREMENT_PROTOCOL. In particular, devicetree,