diff --git a/src/eq_schema/builders/valueSource/index.js b/src/eq_schema/builders/valueSource/index.js
index 3166dc79..9e36da28 100644
--- a/src/eq_schema/builders/valueSource/index.js
+++ b/src/eq_schema/builders/valueSource/index.js
@@ -13,13 +13,20 @@ const getPageByAnswerId = (ctx, answerId) =>
 
 const getValueSource = (ctx, sourceId) => {
   const page = getPageByAnswerId(ctx, sourceId);
-  if (page) {
-    if (page.pageType === "CalculatedSummaryPage") {
+  if (page && page.pageType === "CalculatedSummaryPage") {
+    const calcSumAnswers = flatMap(page.summaryAnswers, (answerId) =>
+      getPageByAnswerId(ctx, answerId)
+    );
+    if (some(calcSumAnswers, { pageType: "CalculatedSummaryPage" })) {
       return {
         identifier: page.id,
-        source: "calculated_summary",
+        source: "grand_calculated_summary",
       };
     }
+    return {
+      identifier: page.id,
+      source: "calculated_summary",
+    };
   }
   return {
     identifier: `answer${sourceId}`,
@@ -28,18 +35,22 @@ const getValueSource = (ctx, sourceId) => {
 };
 
 const getSupplementaryValueSource = (ctx, sourceId) => {
-  const suplementaryField = find(flatMap(ctx.questionnaireJson.supplementaryData.data, "schemaFields"), {id: sourceId});
+  const suplementaryField = find(
+    flatMap(ctx.questionnaireJson.supplementaryData.data, "schemaFields"),
+    { id: sourceId }
+  );
   const source = {
     source: "supplementary_data",
-    identifier: suplementaryField.identifier
-  }
+    identifier: suplementaryField.identifier,
+  };
   if (suplementaryField.selector) {
-    source.selectors = [suplementaryField.selector]
+    source.selectors = [suplementaryField.selector];
   }
-  
+
   return source;
-}
+};
 
 module.exports = {
-  getValueSource, getSupplementaryValueSource
+  getValueSource,
+  getSupplementaryValueSource,
 };