diff --git a/frontend/src/errors/unauthorized.error.js b/frontend/src/errors/unauthorized.error.js
new file mode 100644
index 0000000..6562173
--- /dev/null
+++ b/frontend/src/errors/unauthorized.error.js
@@ -0,0 +1,6 @@
+export class UnauthorizedError extends Error {
+	constructor() {
+		super("Unauthorized");
+		Error.captureStackTrace(this, UnauthorizedError);
+	}
+}
diff --git a/frontend/src/sagas/auth.sagas.js b/frontend/src/sagas/auth.sagas.js
index 3bd9d08..da7d2e2 100644
--- a/frontend/src/sagas/auth.sagas.js
+++ b/frontend/src/sagas/auth.sagas.js
@@ -27,6 +27,7 @@ export function* loginSaga(action) {
 
 
 export function* logoutSaga(action) {
+    const client = new APIClient();
     let result;
     try {
         result = yield call(client.logout);
diff --git a/frontend/src/sagas/failure.sagas.js b/frontend/src/sagas/failure.sagas.js
new file mode 100644
index 0000000..2add5d5
--- /dev/null
+++ b/frontend/src/sagas/failure.sagas.js
@@ -0,0 +1,12 @@
+import { put } from 'redux-saga/effects';
+import { UnauthorizedError } from '../errors/unauthorized.error.js';
+import { addMessage } from '../actions/message.actions.js';
+import { logout } from '../actions/auth.actions.js';
+
+export function* failureActionSaga({ error }) {
+    console.error(error);
+    if (error instanceof UnauthorizedError) {
+        yield put(addMessage('danger', 'Vous avez été déconnecté.'));
+        yield put(logout());
+    }
+}
diff --git a/frontend/src/sagas/root.js b/frontend/src/sagas/root.js
index 845dc31..3576572 100644
--- a/frontend/src/sagas/root.js
+++ b/frontend/src/sagas/root.js
@@ -3,6 +3,7 @@ import { LOGIN_REQUEST, LOGOUT_REQUEST } from '../actions/auth.actions';
 import { loginSaga, logoutSaga }  from './auth.sagas';
 import { PROJECT_USER_LIST, PROJECT_LIST } from '../actions/project';
 import { projectUserListSaga, projectListSaga } from './project';
+import { failureActionSaga } from './failure.sagas';
 
 export default function* rootSaga() {
   yield all([
@@ -10,5 +11,6 @@ export default function* rootSaga() {
     takeLatest(LOGOUT_REQUEST, logoutSaga),
     takeLatest(PROJECT_USER_LIST, projectUserListSaga),
     takeLatest(PROJECT_LIST, projectListSaga),
+    takeLatest(action => /_FAILURE$/g.test(action.type), failureActionSaga),
   ]);
 }
diff --git a/frontend/src/services/api-client.service.js b/frontend/src/services/api-client.service.js
index fb200c7..058bc70 100644
--- a/frontend/src/services/api-client.service.js
+++ b/frontend/src/services/api-client.service.js
@@ -1,7 +1,10 @@
+import { UnauthorizedError } from '../errors/unauthorized.error.js';
+
+export const UnauthorizedStatusCode = 401;
 
 export class APIClient {
   	constructor(baseURL = 'http://localhost:8001/api/v1') {
-    		this.baseURL = baseURL;
+		this.baseURL = baseURL;
 		this.login = this.login.bind(this);
 		this.logout = this.logout.bind(this);
 		this.me = this.me.bind(this);
@@ -47,6 +50,12 @@ export class APIClient {
 		credentials: 'include',
 		body: JSON.stringify(body),
 	  })
+	  .then(res => {
+		if (res.status === UnauthorizedStatusCode) {
+			throw new UnauthorizedError();
+		}
+		return res;
+	  })
 	  .then(res => res.json())
 	}