diff --git a/src/App.js b/src/App.js
index 77a51f9..6dd72a1 100644
--- a/src/App.js
+++ b/src/App.js
@@ -35,9 +35,14 @@ function ChangeFloor({ currentFloor, callbackFloorChanged }) {
       .then(response => response.json())
       .then(data => {
         setSites(data);
+
+        // Display a floor
+        callbackFloorChanged(data[0].buildings[0].floors[0].id)
       });
   }, []);
 
+  if (currentFloor === undefined) return;
+
   var items = [];
 
   sites.forEach(site => {
@@ -110,7 +115,7 @@ function RoomInformation({ roomId, setIsEditDialogOpen }) {
   const [users, setUsers] = React.useState([]);
 
   React.useEffect(() => {
-    if (roomId !== null) {
+    if (roomId !== undefined) {
       fetch("https://encartes.aliens-lyon.fr/api/map/get_place_info/" + roomId)
         .then(response => response.json())
         .then(data => {
@@ -120,7 +125,7 @@ function RoomInformation({ roomId, setIsEditDialogOpen }) {
     }
   }, [roomId]);
 
-  if (roomId === null) {
+  if (roomId === undefined) {
     return;
   }
 
@@ -193,7 +198,7 @@ function EditDialog({ isOpen, setIsOpen, room }) {
   const [updatesCount, setupdatesCount] = React.useState(0);
 
   React.useEffect(() => {
-    if (room !== null) {
+    if (room !== undefined) {
       fetch("https://encartes.aliens-lyon.fr/api/map/get_place_info/" + room)
         .then(response => response.json())
         .then(data => {
@@ -251,8 +256,8 @@ function EditDialog({ isOpen, setIsOpen, room }) {
 }
 
 export default function App() {
-  const [currentFloor, setCurrentFloor] = React.useState(13);
-  const [selectedRoom, setSelectedRoom] = React.useState(null);
+  const [currentFloor, setCurrentFloor] = React.useState(undefined);
+  const [selectedRoom, setSelectedRoom] = React.useState(undefined);
   const [isEditDialogOpen, setIsEditDialogOpen] = React.useState(false);
 
   return <>
@@ -263,12 +268,12 @@ export default function App() {
     />
     <TopBar />
     <div style={{ flexGrow: '1', display: 'flex', flexDirection: 'line', flexWrap: 'nowrap' }}>
-      <Map
+      { currentFloor !== undefined ? <Map
         selectedRoom={selectedRoom}
         callbackRoomSelected={setSelectedRoom}
         floorID={currentFloor}
         callbackChangeFloor={setCurrentFloor}
-      />
+      /> : <></>}
       <div>
         <ChangeFloor currentFloor={currentFloor} callbackFloorChanged={setCurrentFloor} />
         <Divider />