diff --git a/test/unit/model/find-one.test.js b/test/unit/model/find-one.test.js
index d2035bb1ef13..2daa22f50793 100644
--- a/test/unit/model/find-one.test.js
+++ b/test/unit/model/find-one.test.js
@@ -118,6 +118,23 @@ describe(Support.getTestDialectTeaser('Model'), () => {
       });
       Model.findAll = sinon.stub();
 
+      await Model.findOne();
+      Model.findAll.should.not.have.been.called;
+      Sequelize.Model.findAll.should.have.been.called;
+    });
+    it('should call internal findAll() method if findOne() is overridden', async () => {
+      const Model = current.define('model', {
+        unique1: {
+          type: DataTypes.INTEGER,
+          unique: 'unique',
+        },
+        unique2: {
+          type: DataTypes.INTEGER,
+          unique: 'unique',
+        },
+      });
+      Model.findAll = sinon.stub();
+
       await Model.findOne();
       Model.findAll.should.not.have.been.called;
       Sequelize.Model.findAll.should.have.been.called;