diff --git a/app/client/components/GristDoc.ts b/app/client/components/GristDoc.ts
index b170874e..4a2ee69b 100644
--- a/app/client/components/GristDoc.ts
+++ b/app/client/components/GristDoc.ts
@@ -42,16 +42,16 @@ import {startDocTour} from "app/client/ui/DocTour";
 import {showDocSettingsModal} from 'app/client/ui/DocumentSettings';
 import {isTourActive} from "app/client/ui/OnBoardingPopups";
 import {IPageWidget, toPageWidget} from 'app/client/ui/PageWidgetPicker';
-import {IPageWidgetLink, linkFromId, selectBy} from 'app/client/ui/selectBy';
+import {linkFromId, selectBy} from 'app/client/ui/selectBy';
 import {startWelcomeTour} from 'app/client/ui/welcomeTour';
 import {isNarrowScreen, mediaSmall, testId} from 'app/client/ui2018/cssVars';
-import {invokePrompt} from 'app/client/ui2018/modals';
 import {IconName} from 'app/client/ui2018/IconList';
+import {invokePrompt} from 'app/client/ui2018/modals';
 import {FieldEditor} from "app/client/widgets/FieldEditor";
 import {MinimalActionGroup} from 'app/common/ActionGroup';
 import {ClientQuery} from "app/common/ActiveDocAPI";
-import {delay} from 'app/common/delay';
 import {CommDocUsage, CommDocUserAction} from 'app/common/CommTypes';
+import {delay} from 'app/common/delay';
 import {DisposableWithEvents} from 'app/common/DisposableWithEvents';
 import {isSchemaAction, UserAction} from 'app/common/DocActions';
 import {OpenLocalDocResult} from 'app/common/DocListAPI';
@@ -62,8 +62,19 @@ import {LocalPlugin} from "app/common/plugin";
 import {StringUnion} from 'app/common/StringUnion';
 import {TableData} from 'app/common/TableData';
 import {DocStateComparison} from 'app/common/UserAPI';
-import {bundleChanges, Computed, dom, Emitter, Holder, IDisposable, IDomComponent, Observable,
-        styled, subscribe, toKo} from 'grainjs';
+import {
+  bundleChanges,
+  Computed,
+  dom,
+  Emitter,
+  Holder,
+  IDisposable,
+  IDomComponent,
+  Observable,
+  styled,
+  subscribe,
+  toKo
+} from 'grainjs';
 import * as ko from 'knockout';
 import cloneDeepWith = require('lodash/cloneDeepWith');
 import isEqual = require('lodash/isEqual');
@@ -549,7 +560,6 @@ export class GristDoc extends DisposableWithEvents {
    */
   public async addWidgetToPageImpl(val: IPageWidget, tableId: string|null = null) {
     const viewRef = this.activeViewId.get();
-    const link = linkFromId(val.link);
     const tableRef = val.table === 'New Table' ? 0 : val.table;
     const result = await this.docData.sendAction(
       ['CreateViewSection', tableRef, viewRef, val.type, val.summarize ? val.columns : null, tableId]
@@ -557,13 +567,7 @@ export class GristDoc extends DisposableWithEvents {
     if (val.type === 'chart') {
       await this._ensureOneNumericSeries(result.sectionRef);
     }
-    await this.docData.sendAction(
-      ['UpdateRecord', '_grist_Views_section', result.sectionRef, {
-        linkSrcSectionRef: link.srcSectionRef,
-        linkSrcColRef: link.srcColRef,
-        linkTargetColRef: link.targetColRef
-      }]
-    );
+    await this.saveLink(val.link, result.sectionRef);
     return result;
   }
 
@@ -647,7 +651,7 @@ export class GristDoc extends DisposableWithEvents {
 
         // update link
         if (oldVal.link !== newVal.link) {
-          await this.saveLink(linkFromId(newVal.link));
+          await this.saveLink(newVal.link);
         }
         return section;
       },
@@ -698,11 +702,23 @@ export class GristDoc extends DisposableWithEvents {
     }));
   }
 
-  // Save link for the active section.
-  public async saveLink(link: IPageWidgetLink) {
-    const viewModel = this.viewModel;
+  // Save link for a given section, by default the active section.
+  public async saveLink(linkId: string, sectionId?: number) {
+    sectionId = sectionId || this.viewModel.activeSection.peek().getRowId();
+    const link = linkFromId(linkId);
+    if (link.targetColRef) {
+      const targetTable = this.docModel.viewSections.getRowModel(sectionId).table();
+      const targetCol = this.docModel.columns.getRowModel(link.targetColRef);
+      if (targetTable.id() !== targetCol.table().id()) {
+        // targetColRef is actually not a column in the target table.
+        // This should mean that the target table is a summary table (which didn't exist when the
+        // option was selected) and targetColRef is from the source table.
+        // Change it to the corresponding summary table column instead.
+        link.targetColRef = targetTable.columns().all().find(c => c.summarySourceCol() === link.targetColRef)!.id();
+      }
+    }
     return this.docData.sendAction(
-      ['UpdateRecord', '_grist_Views_section', viewModel.activeSection.peek().getRowId(), {
+      ['UpdateRecord', '_grist_Views_section', sectionId, {
         linkSrcSectionRef: link.srcSectionRef,
         linkSrcColRef: link.srcColRef,
         linkTargetColRef: link.targetColRef
diff --git a/app/client/ui/RightPanel.ts b/app/client/ui/RightPanel.ts
index 5c76a055..3c71eb79 100644
--- a/app/client/ui/RightPanel.ts
+++ b/app/client/ui/RightPanel.ts
@@ -25,7 +25,7 @@ import {reportError} from 'app/client/models/AppModel';
 import {ColumnRec, ViewSectionRec} from 'app/client/models/DocModel';
 import {GridOptions} from 'app/client/ui/GridOptions';
 import {attachPageWidgetPicker, IPageWidget, toPageWidget} from 'app/client/ui/PageWidgetPicker';
-import {linkFromId, linkId, selectBy} from 'app/client/ui/selectBy';
+import {linkId, selectBy} from 'app/client/ui/selectBy';
 import {CustomSectionConfig} from 'app/client/ui/CustomSectionConfig';
 import {VisibleFieldsConfig} from 'app/client/ui/VisibleFieldsConfig';
 import {IWidgetType, widgetTypes} from 'app/client/ui/widgetTypes';
@@ -409,7 +409,7 @@ export class RightPanel extends Disposable {
       )
     );
 
-    link.onWrite((val) => this._gristDoc.saveLink(linkFromId(val)));
+    link.onWrite((val) => this._gristDoc.saveLink(val));
     return [
       this._disableIfReadonly(),
       cssLabel('DATA TABLE'),
diff --git a/app/client/ui/selectBy.ts b/app/client/ui/selectBy.ts
index 399a469a..ee2f4811 100644
--- a/app/client/ui/selectBy.ts
+++ b/app/client/ui/selectBy.ts
@@ -4,6 +4,7 @@ import { getReferencedTableId } from 'app/common/gristTypes';
 import { IOptionFull } from 'grainjs';
 import assert from 'assert';
 import * as gutil from "app/common/gutil";
+import isEqual = require('lodash/isEqual');
 
 // some unicode characters
 const BLACK_CIRCLE = '\u2022';
@@ -243,24 +244,44 @@ function fromPageWidget(docModel: DocModel, pageWidget: IPageWidget): LinkNode[]
 
   if (typeof pageWidget.table !== 'number') { return []; }
 
-  const table = docModel.tables.getRowModel(pageWidget.table);
+  let table = docModel.tables.getRowModel(pageWidget.table);
   const isSummary = pageWidget.summarize;
+  const groupbyColumns = isSummary ? new Set(pageWidget.columns) : undefined;
+  let tableExists = true;
+  if (isSummary) {
+    const summaryTable = docModel.tables.rowModels.find(
+      t => t?.summarySourceTable.peek() && isEqual(t.summarySourceColRefs.peek(), groupbyColumns));
+    if (summaryTable) {
+      // The selected source table and groupby columns correspond to this existing summary table.
+      table = summaryTable;
+    } else {
+      // This summary table doesn't exist yet. `fromColumns` will be using columns from the source table.
+      // Make sure it only uses columns that are in the selected groupby columns.
+      // The resulting targetColRef will incorrectly be from the source table,
+      // but will be corrected in GristDoc.saveLink after the summary table is created.
+      tableExists = false;
+    }
+  }
+
   const mainNode: LinkNode = {
     tableId: table.primaryTableId.peek(),
     isSummary,
-    groupbyColumns: isSummary ? new Set(pageWidget.columns) : undefined,
+    groupbyColumns,
     widgetType: pageWidget.type,
     ancestors: new Set(),
     section: docModel.viewSections.getRowModel(pageWidget.section),
   };
 
-  return fromColumns(table, mainNode);
+  return fromColumns(table, mainNode, tableExists);
 }
 
-function fromColumns(table: TableRec, mainNode: LinkNode): LinkNode[] {
+function fromColumns(table: TableRec, mainNode: LinkNode, tableExists: boolean = true): LinkNode[] {
   const nodes = [mainNode];
   const columns = table.columns.peek().peek();
   for (const column of columns) {
+    if (!tableExists && !mainNode.groupbyColumns!.has(column.getRowId())) {
+      continue;
+    }
     const tableId = getReferencedTableId(column.type.peek());
     if (tableId) {
       nodes.push({...mainNode, tableId, column});
diff --git a/test/nbrowser/gristUtils.ts b/test/nbrowser/gristUtils.ts
index c42b1204..0aa78a3b 100644
--- a/test/nbrowser/gristUtils.ts
+++ b/test/nbrowser/gristUtils.ts
@@ -871,6 +871,7 @@ export interface PageWidgetPickerOptions {
   tableName?: string;
   selectBy?: RegExp|string;      // Optional pattern of SELECT BY option to pick.
   summarize?: (RegExp|string)[];   // Optional list of patterns to match Group By columns.
+  dontAdd?: boolean;  // If true, configure the widget selection without actually adding to the page
 }
 
 // Add a new page using the 'Add New' menu and wait for the new page to be shown.
@@ -939,8 +940,14 @@ export async function selectWidget(
     await driver.findContent('.test-wselect-selectby option', options.selectBy).doClick();
   }
 
-  // let's select right type and save
+  // select right type
   await driver.findContent('.test-wselect-type', typeRe).doClick();
+
+  if (options.dontAdd) {
+    return;
+  }
+
+  // add the widget
   await driver.find('.test-wselect-addBtn').doClick();
 
   // if we selected a new table, there will be a popup for a name