'ion-tab' is not a known element

<ion-tabs>
    <ion-tab tab="makuuchi">
        <ion-header translucent>
            <ion-toolbar>
                <ion-title>Makuuchi</ion-title>
            </ion-toolbar>
        </ion-header>
        <ion-content fullscreen class="ion-padding">
            <h1>Makuuchi</h1>
        </ion-content>
    </ion-tab>
    <ion-tab-bar slot="top">
        <ion-tab-button tab="makuuchi">
            <ion-label>Makuuchi</ion-label>
            <ion-icon name="people"></ion-icon>
        </ion-tab-button>
        <ion-tab-button tab="juryo">
            <ion-label>Juryo</ion-label>
            <ion-icon name="people"></ion-icon>
        </ion-tab-button>
    </ion-tab-bar>
</ion-tabs>

"dependencies": {
    "@angular/common": "^7.2.2",
    "@angular/core": "^7.2.2",
    "@angular/forms": "^7.2.2",
    "@angular/http": "^7.2.2",
    "@angular/platform-browser": "^7.2.2",
    "@angular/platform-browser-dynamic": "^7.2.2",
    "@angular/router": "^7.2.2",
    "@ionic-native/core": "^5.0.0",
    "@ionic-native/splash-screen": "^5.0.0",
    "@ionic-native/status-bar": "^5.0.0",
    "@ionic/angular": "^4.1.0",
    "core-js": "^2.5.4",
    "rxjs": "~6.5.1",
    "tslib": "^1.9.0",
    "zone.js": "~0.8.29"
  },

Ionic:
   Ionic CLI                     : 5.0.2 (/home/christophe/.nvm/versions/node/v8.10.0/lib/node_modules/ionic)
   Ionic Framework               : @ionic/angular 4.5.0
   @angular-devkit/build-angular : 0.13.9
   @angular-devkit/schematics    : 7.3.9
   @angular/cli                  : 7.3.9
   @ionic/angular-toolkit        : 1.5.1
Utility:
   cordova-res : not installed
   native-run  : not installed
System:
   NodeJS : v8.10.0 (/home/christophe/.nvm/versions/node/v8.10.0/bin/node)
   npm    : 6.9.0
   OS     : Linux 4.18