diff --git a/lib/plugins/mongoose-encryption.js b/lib/plugins/mongoose-encryption.js
index c91bf8f..c21ae00 100644
--- a/lib/plugins/mongoose-encryption.js
+++ b/lib/plugins/mongoose-encryption.js
@@ -345,6 +345,10 @@ var mongooseEncryption = function(schema, options) {
             // remove encrypted fields from cleartext
             encryptedFields.forEach(function(field){
                 setFieldValue(that, field, undefined);
+                // prevent conflict errors due to array change tracking in Mongoose 6
+                if (that.schema.paths[field].$isMongooseArray) {
+                    that.unmarkModified(field);
+                }
             });
 
             cb(null);
diff --git a/test/encrypt.coffee b/test/encrypt.coffee
index 6b10429..4c48f31 100644
--- a/test/encrypt.coffee
+++ b/test/encrypt.coffee
@@ -1128,6 +1128,48 @@ describe 'Array EmbeddedDocument', ->
               done()
         return
 
+  describe 'when entire children array is encrypted', ->
+    before ->
+      ChildModelSchema = mongoose.Schema
+        text: type: String
+
+      ParentModelSchema = mongoose.Schema
+        children: [ChildModelSchema]
+
+      ParentModelSchema.plugin encrypt,
+        encryptionKey: encryptionKey,
+        signingKey: signingKey
+        encryptedFields: ['children']
+
+      @ParentModel = mongoose.model 'EncChildrenArrayParent', ParentModelSchema
+      @ChildModel = mongoose.model 'EncChildrenArrayChild', ChildModelSchema
+
+    beforeEach (done) ->
+      @parentDoc = new @ParentModel
+
+      childDoc = new @ChildModel
+        text: 'Child unencrypted text'
+
+      @parentDoc.children.addToSet childDoc
+
+      @parentDoc.save done
+
+    after (done) ->
+      @parentDoc.remove done
+
+    describe 'document.save()', ->
+      it 'should save changes to encrypted children', (done) ->
+        @ParentModel.findById @parentDoc._id, (err, doc) =>
+          assert.equal err, null
+          doc.children[0].text = 'New unencrypted text'
+          doc.save (err) =>
+            assert.equal err, null
+            @ParentModel.findById doc._id, (err, updatedDoc) ->
+              assert.equal err, null
+              assert.equal updatedDoc.children[0].text, 'New unencrypted text'
+              done()
+        return
+
   describe 'when child and parent are encrypted', ->
     before ->
       ChildModelSchema = mongoose.Schema