diff --git a/lib/types/documentarray.js b/lib/types/documentarray.js
index 87757e4f171..b9cc33cd24d 100644
--- a/lib/types/documentarray.js
+++ b/lib/types/documentarray.js
@@ -328,18 +328,18 @@ if (util.inspect.custom) {
 
 function _updateParentPopulated(arr) {
   const parent = arr[arrayParentSymbol];
-  if (parent.$__.populated != null) {
-    const populatedPaths = Object.keys(parent.$__.populated).
-      filter(p => p.startsWith(arr[arrayPathSymbol] + '.'));
+  if (!parent || parent.$__.populated == null) return;
 
-    for (const path of populatedPaths) {
-      const remnant = path.slice((arr[arrayPathSymbol] + '.').length);
-      if (!Array.isArray(parent.$__.populated[path].value)) {
-        continue;
-      }
+  const populatedPaths = Object.keys(parent.$__.populated).
+    filter(p => p.startsWith(arr[arrayPathSymbol] + '.'));
 
-      parent.$__.populated[path].value = arr.map(val => val.populated(remnant));
+  for (const path of populatedPaths) {
+    const remnant = path.slice((arr[arrayPathSymbol] + '.').length);
+    if (!Array.isArray(parent.$__.populated[path].value)) {
+      continue;
     }
+
+    parent.$__.populated[path].value = arr.map(val => val.populated(remnant));
   }
 }
 
diff --git a/test/types.documentarray.test.js b/test/types.documentarray.test.js
index 1a148714750..8140ee484b0 100644
--- a/test/types.documentarray.test.js
+++ b/test/types.documentarray.test.js
@@ -575,6 +575,19 @@ describe('types.documentarray', function() {
       assert.equal(arr.length, 1);
       assert.equal(doc.docs.length, 2);
     });
+
+    it('map() works', function() {
+      const personSchema = new Schema({ friends: [{ name: { type: String } }]});
+      const Person = mongoose.model('gh8317-map', personSchema);
+
+      const person = new Person({ friends: [{ name: 'Hafez' }] });
+
+      const friendsNames = person.friends.map(friend => friend.name);
+      friendsNames.push('Sam');
+
+      assert.equal(friendsNames.length, 2);
+      assert.equal(friendsNames[1], 'Sam');
+    });
   });
 
   it('cleans modified subpaths on splice() (gh-7249)', function() {