diff --git a/ui/src/pages/Pivot.jsx b/ui/src/pages/Pivot.jsx
index bb5c1b1..027b064 100644
--- a/ui/src/pages/Pivot.jsx
+++ b/ui/src/pages/Pivot.jsx
@@ -173,11 +173,13 @@ export default function Pivot({ source }) {
         function cleanLayout(cfg) {
           if (!cfg) return cfg
           const clean = { ...cfg }
-          if (clean.columns) clean.columns = clean.columns.filter(c => c == null || validCols.has(c))
-          if (clean.group_by) clean.group_by = clean.group_by.filter(c => validCols.has(c))
-          if (clean.split_by) clean.split_by = clean.split_by.filter(c => validCols.has(c))
-          if (clean.sort) clean.sort = clean.sort.filter(([c]) => validCols.has(c))
-          if (clean.filter) clean.filter = clean.filter.filter(([c]) => validCols.has(c))
+          const exprNames = new Set(Object.keys(clean.expressions || {}))
+          const valid = (c) => validCols.has(c) || exprNames.has(c)
+          if (clean.columns) clean.columns = clean.columns.filter(c => c == null || valid(c))
+          if (clean.group_by) clean.group_by = clean.group_by.filter(valid)
+          if (clean.split_by) clean.split_by = clean.split_by.filter(valid)
+          if (clean.sort) clean.sort = clean.sort.filter(([c]) => valid(c))
+          if (clean.filter) clean.filter = clean.filter.filter(([c]) => valid(c))
           return clean
         }
 
@@ -257,11 +259,13 @@ export default function Pivot({ source }) {
       function cleanLayout(cfg) {
         if (!cfg) return cfg
         const clean = { ...cfg }
-        if (clean.columns) clean.columns = clean.columns.filter(c => c == null || validCols.has(c))
-        if (clean.group_by) clean.group_by = clean.group_by.filter(c => validCols.has(c))
-        if (clean.split_by) clean.split_by = clean.split_by.filter(c => validCols.has(c))
-        if (clean.sort) clean.sort = clean.sort.filter(([c]) => validCols.has(c))
-        if (clean.filter) clean.filter = clean.filter.filter(([c]) => validCols.has(c))
+        const exprNames = new Set(Object.keys(clean.expressions || {}))
+        const valid = (c) => validCols.has(c) || exprNames.has(c)
+        if (clean.columns) clean.columns = clean.columns.filter(c => c == null || valid(c))
+        if (clean.group_by) clean.group_by = clean.group_by.filter(valid)
+        if (clean.split_by) clean.split_by = clean.split_by.filter(valid)
+        if (clean.sort) clean.sort = clean.sort.filter(([c]) => valid(c))
+        if (clean.filter) clean.filter = clean.filter.filter(([c]) => valid(c))
         return clean
       }
       const cleaned = cleanLayout(layout.config)