diff --git a/ui/src/views/Forecast.jsx b/ui/src/views/Forecast.jsx
index 0d2c1ab..2eb268b 100644
--- a/ui/src/views/Forecast.jsx
+++ b/ui/src/views/Forecast.jsx
@@ -48,7 +48,18 @@ function cleanLayout(cfg, validCols) {
 // double quotes, string literals in single, if/else with braces. The ordered
 // label is emitted as a literal rather than built with concat() — fewer moving
 // parts, and the mapping is known here anyway.
-const ORDER_EXPR_NAMES = { bucket: 'Bucket', segment: 'Segment' }
+// pf_ prefixed like every other column the server synthesises, so they sort
+// beside pf_bucket and pf_segment in the column list and cannot be mistaken for
+// source data. "Bucket" and "Segment" were the first choice and are too close to
+// the real thing -- segment_new is an actual column on this source -- and an
+// expression named after an existing column would shadow or reject rather than
+// merely confuse.
+const ORDER_EXPR_NAMES = { bucket: 'pf_bucket_ord', segment: 'pf_segment_ord' }
+
+// Removed from any config that still carries them. They are no longer managed
+// names, so without this they would sit in saved layouts forever, ordering by a
+// rule nothing updates.
+const LEGACY_ORDER_EXPR_NAMES = ['Bucket', 'Segment']
 
 // ASCII only, and " - " specifically because the source data already reads
 // "07 - Dec". A middle dot was the first choice and ExprTK rejects it: its string
@@ -972,7 +983,7 @@ export default function Forecast({ sources = [], sourceId, versions = [], versio
     const { table: _t, ...cfg } = await viewer.save()
     dbgOrder('saved config read', { existing: Object.keys(cfg.expressions || {}) })
     const current = cfg.expressions || {}
-    const managed = Object.values(ORDER_EXPR_NAMES)
+    const managed = [...Object.values(ORDER_EXPR_NAMES), ...LEGACY_ORDER_EXPR_NAMES]
 
     const next = { ...current }
     for (const name of managed) delete next[name]