diff --git a/lib/connection.js b/lib/connection.js
index 2f847bffc2f..247fe8f58a9 100644
--- a/lib/connection.js
+++ b/lib/connection.js
@@ -81,7 +81,7 @@ function Connection(base) {
  * Inherit from EventEmitter
  */
 
-Connection.prototype.__proto__ = EventEmitter.prototype;
+Object.setPrototypeOf(Connection.prototype, EventEmitter.prototype);
 
 /**
  * Connection ready state
diff --git a/lib/drivers/node-mongodb-native/collection.js b/lib/drivers/node-mongodb-native/collection.js
index b390fa1f349..54963c40c7d 100644
--- a/lib/drivers/node-mongodb-native/collection.js
+++ b/lib/drivers/node-mongodb-native/collection.js
@@ -34,7 +34,7 @@ function NativeCollection(name, conn, options) {
  * Inherit from abstract Collection.
  */
 
-NativeCollection.prototype.__proto__ = MongooseCollection.prototype;
+Object.setPrototypeOf(NativeCollection.prototype, MongooseCollection.prototype);
 
 /**
  * Called when the connection opens.
diff --git a/lib/drivers/node-mongodb-native/connection.js b/lib/drivers/node-mongodb-native/connection.js
index 1adad7cd8b5..5c6976d92b4 100644
--- a/lib/drivers/node-mongodb-native/connection.js
+++ b/lib/drivers/node-mongodb-native/connection.js
@@ -32,7 +32,7 @@ NativeConnection.STATES = STATES;
  * Inherits from Connection.
  */
 
-NativeConnection.prototype.__proto__ = MongooseConnection.prototype;
+Object.setPrototypeOf(NativeConnection.prototype, MongooseConnection.prototype);
 
 /**
  * Switches to a different database using the same connection pool.
diff --git a/lib/model.js b/lib/model.js
index 7ed676f0677..0c835c4ec01 100644
--- a/lib/model.js
+++ b/lib/model.js
@@ -126,7 +126,7 @@ function Model(doc, fields, skipId) {
  * top level (non-sub) documents.
  */
 
-Model.prototype.__proto__ = Document.prototype;
+Object.setPrototypeOf(Model.prototype, Document.prototype);
 Model.prototype.$isMongooseModelPrototype = true;
 
 /**
@@ -1218,7 +1218,7 @@ Model.discriminator = function(name, schema, options) {
   model = this.db.model(model || name, schema, this.$__collection.name);
   this.discriminators[name] = model;
   const d = this.discriminators[name];
-  d.prototype.__proto__ = this.prototype;
+  Object.setPrototypeOf(d.prototype, this.prototype);
   Object.defineProperty(d, 'baseModelName', {
     value: this.modelName,
     configurable: true,
@@ -4944,8 +4944,8 @@ Model.compile = function compile(name, schema, collectionName, connection, base)
   model.modelName = name;
 
   if (!(model.prototype instanceof Model)) {
-    model.__proto__ = Model;
-    model.prototype.__proto__ = Model.prototype;
+    Object.setPrototypeOf(model, Model);
+    Object.setPrototypeOf(model.prototype, Model.prototype);
   }
   model.model = function model(name) {
     return this.db.model(name);
@@ -5037,8 +5037,8 @@ Model.__subclass = function subclass(conn, schema, collection) {
     _this.call(this, doc, fields, skipId);
   };
 
-  Model.__proto__ = _this;
-  Model.prototype.__proto__ = _this.prototype;
+  Object.setPrototypeOf(Model, _this);
+  Object.setPrototypeOf(Model.prototype, _this.prototype);
   Model.db = conn;
   Model.prototype.db = conn;
   Model.prototype[modelDbSymbol] = conn;
diff --git a/test/document.isselected.test.js b/test/document.isselected.test.js
index d013eed5efb..3f25b34ac2f 100644
--- a/test/document.isselected.test.js
+++ b/test/document.isselected.test.js
@@ -27,7 +27,7 @@ function TestDocument() {
  * Inherits from Document.
  */
 
-TestDocument.prototype.__proto__ = Document.prototype;
+Object.setPrototypeOf(TestDocument.prototype, Document.prototype);
 
 for (const i in EventEmitter.prototype) {
   TestDocument[i] = EventEmitter.prototype[i];
diff --git a/test/document.populate.test.js b/test/document.populate.test.js
index 45a7c308ba8..efb8848cd98 100644
--- a/test/document.populate.test.js
+++ b/test/document.populate.test.js
@@ -30,7 +30,7 @@ function TestDocument() {
  * Inherits from Document.
  */
 
-TestDocument.prototype.__proto__ = Document.prototype;
+Object.setPrototypeOf(TestDocument.prototype, Document.prototype);
 
 /**
  * Set a dummy schema to simulate compilation.
diff --git a/test/document.test.js b/test/document.test.js
index 816d6885f18..d1f36fd4b03 100644
--- a/test/document.test.js
+++ b/test/document.test.js
@@ -38,7 +38,7 @@ function TestDocument() {
  * Inherits from Document.
  */
 
-TestDocument.prototype.__proto__ = Document.prototype;
+Object.setPrototypeOf(TestDocument.prototype, Document.prototype);
 
 for (const i in EventEmitter.prototype) {
   TestDocument[i] = EventEmitter.prototype[i];
diff --git a/test/document.unit.test.js b/test/document.unit.test.js
index 0ebdc16dc1b..dbae16908ac 100644
--- a/test/document.unit.test.js
+++ b/test/document.unit.test.js
@@ -22,7 +22,7 @@ describe('sharding', function() {
       this.$__schema = mockSchema;
       this.$__ = {};
     };
-    Stub.prototype.__proto__ = mongoose.Document.prototype;
+    Object.setPrototypeOf(Stub.prototype, mongoose.Document.prototype);
     const d = new Stub();
     const currentTime = new Date();
     d._doc = { date: currentTime };
diff --git a/test/model.discriminator.test.js b/test/model.discriminator.test.js
index 337dae25d6d..22f33166acf 100644
--- a/test/model.discriminator.test.js
+++ b/test/model.discriminator.test.js
@@ -96,8 +96,6 @@ describe('model', function() {
       const employee = new Employee();
       assert.ok(employee instanceof Person);
       assert.ok(employee instanceof Employee);
-      assert.strictEqual(employee.__proto__.constructor, Employee);
-      assert.strictEqual(employee.__proto__.__proto__.constructor, Person);
     });
 
     it('can define static and instance methods', function() {
diff --git a/test/schema.test.js b/test/schema.test.js
index 4b7129ca46a..c09895de3b3 100644
--- a/test/schema.test.js
+++ b/test/schema.test.js
@@ -33,7 +33,7 @@ function TestDocument() {
  * Inherits from Document.
  */
 
-TestDocument.prototype.__proto__ = Document.prototype;
+Object.setPrototypeOf(TestDocument.prototype, Document.prototype);
 
 /**
  * Test.
diff --git a/test/types.document.test.js b/test/types.document.test.js
index fc101692390..d30f6e45119 100644
--- a/test/types.document.test.js
+++ b/test/types.document.test.js
@@ -33,7 +33,7 @@ describe('types.document', function() {
       mongoose.Document.call(this, {});
     }
     Dummy = _Dummy;
-    Dummy.prototype.__proto__ = mongoose.Document.prototype;
+    Object.setPrototypeOf(Dummy.prototype, mongoose.Document.prototype);
     Dummy.prototype.$__setSchema(new Schema());
 
     function _Subdocument() {
@@ -43,7 +43,7 @@ describe('types.document', function() {
     }
     Subdocument = _Subdocument;
 
-    Subdocument.prototype.__proto__ = ArraySubdocument.prototype;
+    Object.setPrototypeOf(Subdocument.prototype, ArraySubdocument.prototype);
 
     for (const i in EventEmitter.prototype) {
       Subdocument[i] = EventEmitter.prototype[i];
diff --git a/test/types.documentarray.test.js b/test/types.documentarray.test.js
index 6ee188f9eb4..1ab1447e25d 100644
--- a/test/types.documentarray.test.js
+++ b/test/types.documentarray.test.js
@@ -29,7 +29,7 @@ function TestDoc(schema) {
    * Inherits from ArraySubdocument.
    */
 
-  Subdocument.prototype.__proto__ = ArraySubdocument.prototype;
+  Object.setPrototypeOf(Subdocument.prototype, ArraySubdocument.prototype);
 
   /**
    * Set schema.