[(ngModel)] not works: Can't bind to 'ngModel' since it isn't a known property of 'ng-select'.

I’m trying to use the official example, but I can not make it work. The example and the page not load. This error message appears in console:

Uncaught Error: Template parse errors:
Can't bind to 'ngModel' since it isn't a known property of 'ng-select'.
1. If 'ngModel' is an Angular directive, then add 'CommonModule' to the '@NgModule.imports' of this component.
2. To allow any property add 'NO_ERRORS_SCHEMA' to the '@NgModule.schemas' of this component. ("

           placeholder="Select city"
           [ERROR ->][(ngModel)]="selectedItem"
           >
</ng-select>
"): ng:///SalesModule/SaleListComponent.html@5:11
    at syntaxError (compiler.js:485)
    at TemplateParser.parse (compiler.js:24661)
    at JitCompiler._parseTemplate (compiler.js:34601)
    at JitCompiler._compileTemplate (compiler.js:34576)
    at eval (compiler.js:34477)
    at Set.forEach (<anonymous>)
    at JitCompiler._compileComponents (compiler.js:34477)
    at eval (compiler.js:34347)
    at Object.then (compiler.js:474)
    at JitCompiler._compileModuleAndComponents (compiler.js:34346)

My code:

<ng-select [items]="cities"
           bindLabel="name"
           bindValue="id"

           placeholder="Select city"
           [(ngModel)]="selectedItem"
           >
</ng-select>

And:

import { Component, OnInit } from '@angular/core';
import {NgOption} from "@ng-select/ng-select";

@Component({
  selector: 'sale-list',
  templateUrl: './sale-list.component.html',
  styleUrls: ['./sale-list.component.css']
})
export class SaleListComponent implements OnInit {

    cities: NgOption[] = [
        {id: 1, name: 'Vilnius'},
        {id: 2, name: 'Kaunas'},
        {id: 3, name: 'Pabradė'},
        {id: 3, name: 'Klaipėda'},
        {id: 3, name: 'Nida'}
    ];
    selectedItem: any;

  constructor(
  ) { }

  ngOnInit() {
      this.selectedItem = this.cities[0].id;
  }

}

The example works fine when I remove the label [(ngModel)]. The page also works and there is no error using (ngModel), but the one-bind does not seem to work. [ngModel] also causes the error.

Packages:

  "name": "xxxxx",
  "version": "0.0.0",
  "license": "MIT",
  "scripts": {
    "ng": "ng",
    "start": "ng serve --proxy-config proxy.conf.js",
    "build": "ng build --prod",
    "test": "ng test",
    "lint": "ng lint",
    "e2e": "ng e2e"
  },
  "private": true,
  "dependencies": {
    "@angular/animations": "^5.1.0",
    "@angular/common": "^5.1.0",
    "@angular/compiler": "^5.1.0",
    "@angular/core": "^5.1.0",
    "@angular/forms": "^5.1.0",
    "@angular/http": "^5.1.0",
    "@angular/platform-browser": "^5.1.0",
    "@angular/platform-browser-dynamic": "^5.1.0",
    "@angular/router": "^5.1.0",
    "@ng-bootstrap/ng-bootstrap": "^1.0.0-beta.9",
    "@ng-select/ng-select": "^0.11.0",
    "bootstrap": "^4.0.0-beta.3",
    "core-js": "^2.4.1",
    "rxjs": "^5.5.6",
    "zone.js": "^0.8.19"
  },
  "devDependencies": {
    "@angular/cli": "1.6.4",
    "@angular/compiler-cli": "^5.1.0",
    "@angular/language-service": "^5.2.0",
    "@types/jasmine": "~2.8.3",
    "@types/jasminewd2": "~2.0.2",
    "@types/node": "~6.0.60",
    "codelyzer": "^4.0.1",
    "jasmine-core": "~2.8.0",
    "jasmine-spec-reporter": "~4.2.1",
    "karma": "~2.0.0",
    "karma-chrome-launcher": "~2.2.0",
    "karma-cli": "~1.0.1",
    "karma-coverage-istanbul-reporter": "^1.2.1",
    "karma-jasmine": "~1.1.0",
    "karma-jasmine-html-reporter": "^0.2.2",
    "protractor": "~5.1.2",
    "ts-node": "~3.2.0",
    "tslint": "~5.9.1",
    "typescript": "~2.5.3"
  }
}

Project using Angular Cli. ng-select version: latest version and 0.11.0. browser: Chromium 63.0.3239.108 reproducible in demo page: NO

[Nekmo]

Resolved including modules:

        FormsModule,
        ReactiveFormsModule,

[jbiddulph]

I’m having this issue, I added FormsModule and ReactiveFormsModule to app.module.ts and to the actual module file… I am still getting the error?!