diff --git a/ui/src/views/Forecast.jsx b/ui/src/views/Forecast.jsx
index f25f293..34305d5 100644
--- a/ui/src/views/Forecast.jsx
+++ b/ui/src/views/Forecast.jsx
@@ -1307,7 +1307,7 @@ export default function Forecast({ sources = [], sourceId, versions = [], versio
     // changes a larger set. It travels as [col, op, value] rather than folded
     // into the slices, because a slice is {col: value} and can only mean
     // equality: a view filtered to sseas_e <= 2027 has no slice form at all.
-    const body = buildPayload(op, viewFilterRef.current)
+    const body = buildPayload(op)
     if (!body) return
     if (body.slices.some(sl => !Object.keys(sl).length)) {
       flash('No dimension or date columns in slice — check col_meta', 'error'); return
@@ -1436,7 +1436,11 @@ export default function Forecast({ sources = [], sourceId, versions = [], versio
     return out
   }
 
-  function buildPayload(op, viewFilter = []) {
+  // The scope is read from the ref rather than passed in: the request preview in
+  // the panel calls this too, and when it was a parameter the preview defaulted
+  // it away -- showing a payload with no scope for a write that had one.
+  function buildPayload(op) {
+    const viewFilter = viewFilterRef.current || []
     if (!slices.length) return null
     // Two clicked cells can differ only by a column the operation cannot filter on
     // (pf_iter, say, which is not in col_meta and so is dropped here). Those become