diff --git a/lib/helpers/populate/assignRawDocsToIdStructure.js b/lib/helpers/populate/assignRawDocsToIdStructure.js
index be39c370dd8..e04b601ba97 100644
--- a/lib/helpers/populate/assignRawDocsToIdStructure.js
+++ b/lib/helpers/populate/assignRawDocsToIdStructure.js
@@ -6,6 +6,8 @@ const utils = require('../../utils');
 
 module.exports = assignRawDocsToIdStructure;
 
+const kHasArray = Symbol('assignRawDocsToIdStructure.hasArray');
+
 /**
  * Assign `vals` returned by mongo query to the `rawIds`
  * structure returned from utils.getVals() honoring
@@ -43,7 +45,16 @@ function assignRawDocsToIdStructure(rawIds, resultDocs, resultOrder, options, re
 
   let i = 0;
   const len = rawIds.length;
-  const hasResultArrays = Object.values(resultOrder).find(o => Array.isArray(o));
+
+  if (sorting && recursed && options[kHasArray] === undefined) {
+    options[kHasArray] = false;
+    for (const key in resultOrder) {
+      if (Array.isArray(resultOrder[key])) {
+        options[kHasArray] = true;
+        break;
+      }
+    }
+  }
 
   for (i = 0; i < len; ++i) {
     id = rawIds[i];
@@ -55,7 +66,7 @@ function assignRawDocsToIdStructure(rawIds, resultDocs, resultOrder, options, re
       continue;
     }
 
-    if (id === null && !sorting) {
+    if (id === null && sorting === false) {
       // keep nulls for findOne unless sorting, which always
       // removes them (backward compat)
       newOrder.push(id);
@@ -79,7 +90,7 @@ function assignRawDocsToIdStructure(rawIds, resultDocs, resultOrder, options, re
       if (doc) {
         if (sorting) {
           const _resultOrder = resultOrder[sid];
-          if (hasResultArrays) {
+          if (options[kHasArray]) {
             // If result arrays, rely on the MongoDB server response for ordering
             newOrder.push(doc);
           } else {