diff --git a/ui/src/views/Forecast.jsx b/ui/src/views/Forecast.jsx
index 1ed44fb..ec204f4 100644
--- a/ui/src/views/Forecast.jsx
+++ b/ui/src/views/Forecast.jsx
@@ -18,7 +18,8 @@ function loadPerspective() {
 function cleanLayout(cfg, validCols) {
   if (!cfg) return cfg
   const c = { ...cfg }
-  const ok = (col) => validCols.has(col)
+  const exprNames = new Set(Object.keys(cfg.expressions || {}))
+  const ok = (col) => validCols.has(col) || exprNames.has(col)
   if (c.columns)  c.columns  = c.columns.filter(col => col == null || ok(col))
   if (c.group_by) c.group_by = c.group_by.filter(ok)
   if (c.split_by) c.split_by = c.split_by.filter(ok)