diff --git a/examples/simple/simple.ino b/examples/simple/simple.ino
index 5b93390..424560e 100644
--- a/examples/simple/simple.ino
+++ b/examples/simple/simple.ino
@@ -1,17 +1,35 @@
-#ifdef ESP32
+#if defined(ESP32)
 #include <WiFi.h>
-#else
+#elif defined(ESP8266)
 #include <ESP8266WiFi.h>
+#else
+#error Platform not supported
 #endif
+
 #include <ESPAsyncWebServer.h>
-#include <LittleFS.h>
 #include <AsyncWebdav.h>
 
+// LittleFS
+#include <LittleFS.h>
+#define FILESYSTEM LittleFS
+
+// SPIFFS
+// #include <SPIFFS.h>
+// #define FILESYSTEM SPIFFS
+
+// FFat
+// #include <FFat.h>
+// #define FILESYSTEM FFat
+
 const char* ssid = "ssid";
 const char* password = "pass";
 
 AsyncWebServer server(80);
-AsyncWebdav dav("/dav", LittleFS);
+
+size_t totalBytes() { return FILESYSTEM.totalBytes(); }
+size_t usedBytes() { return FILESYSTEM.usedBytes(); }
+
+AsyncWebdav dav("/dav", FILESYSTEM, totalBytes, usedBytes);
 
 
 void setup(void){
@@ -31,14 +49,14 @@ void setup(void){
   Serial.print("IP address: ");
   Serial.println(WiFi.localIP());
 
-  // init spiffs
-  LittleFS.begin();
+  // init filesystem
+  FILESYSTEM.begin();
 
-  // add websocket handler
+  // add WebDAV handler
   server.addHandler(&dav);
 
   // start webserver
-  server.serveStatic("/", LittleFS, "/").setDefaultFile("index.html");
+  server.serveStatic("/", FILESYSTEM, "/www/").setDefaultFile("index.html");
   server.begin();
 }
 
diff --git a/library.json b/library.json
index 449ed88..445f16d 100644
--- a/library.json
+++ b/library.json
@@ -12,6 +12,12 @@
     "type": "git",
     "url": "https://github.com/rostwolke/ESPAsyncWebdav"
   },
+  "dependencies": [
+    {
+      "name":"ESP Async WebServer",
+      "version":"https://github.com/rostwolke/ESPAsyncWebServer"
+    }
+  ],  
   "frameworks": "arduino",
   "platforms":"espressif"
 }
diff --git a/src/AsyncWebdav.cpp b/src/AsyncWebdav.cpp
index 98c370a..9651be5 100644
--- a/src/AsyncWebdav.cpp
+++ b/src/AsyncWebdav.cpp
@@ -1,6 +1,6 @@
 #include <Arduino.h>
 #include <ESPAsyncWebServer.h>
-#include <DateTime.h>
+// #include <DateTime.h>
 
 #ifdef ESP32
     #include <AsyncTCP.h>
@@ -14,11 +14,13 @@
 
 #include "AsyncWebdav.h"
 
-AsyncWebdav::AsyncWebdav(const String& url, fs::FS &fs) : _fs(fs) {
-    this->_url = url;
+AsyncWebdav::AsyncWebdav(const String& url, fs::FS &fs, quota_function totalBytes, quota_function usedBytes)
+: _url(url)
+, _fs(fs)
+, _totalBytes(totalBytes)
+, _usedBytes(usedBytes) {
 }
 
-
 bool AsyncWebdav::canHandle(AsyncWebServerRequest *request){
     if(request->url().startsWith(this->_url)){
         if(request->method() == HTTP_PROPFIND 
@@ -357,8 +359,9 @@ void AsyncWebdav::sendPropResponse(AsyncResponseStream *response, boolean recurs
 
     // get file modified time
     time_t lastWrite = curFile->getLastWrite();
-    DateTimeClass dt(lastWrite);
-    String fileTimeStamp = dt.format("%a, %d %b %Y %H:%M:%S GMT");
+    char fileTimeStamp[64];
+    struct tm* t = localtime(&lastWrite);
+    strftime(fileTimeStamp, sizeof(fileTimeStamp), "%a, %d %b %Y %H:%M:%S GMT", t);
 
     // send response
     response->print("<d:response>");
@@ -367,7 +370,18 @@ void AsyncWebdav::sendPropResponse(AsyncResponseStream *response, boolean recurs
     response->print("<d:prop>");
     
     // last modified
-    response->printf("<d:getlastmodified>%s</d:getlastmodified>", fileTimeStamp.c_str());
+    response->printf("<d:getlastmodified>%s</d:getlastmodified>", fileTimeStamp);
+
+    // quota
+    size_t usedBytes = 0;
+    size_t availBytes = 0;
+    
+    if (_totalBytes && _usedBytes) {
+        usedBytes = _usedBytes();
+        availBytes = _totalBytes() - usedBytes;
+    }
+    response->printf("<d:quota-used-bytes>%d</d:quota-used-bytes>", usedBytes);
+    response->printf("<d:quota-available-bytes>%d</d:quota-available-bytes>", availBytes);
 
     if(curFile->isDirectory()) {
         // resource type
diff --git a/src/AsyncWebdav.h b/src/AsyncWebdav.h
index 9c834a3..21f1f62 100644
--- a/src/AsyncWebdav.h
+++ b/src/AsyncWebdav.h
@@ -1,6 +1,6 @@
 #include <Arduino.h>
 #include <FS.h>
-
+#include <ESPAsyncWebServer.h>
 
 enum DavResourceType { DAV_RESOURCE_NONE, DAV_RESOURCE_FILE, DAV_RESOURCE_DIR };
 enum DavDepthType { DAV_DEPTH_NONE, DAV_DEPTH_CHILD, DAV_DEPTH_ALL };
@@ -8,7 +8,10 @@ enum DavDepthType { DAV_DEPTH_NONE, DAV_DEPTH_CHILD, DAV_DEPTH_ALL };
 
 class AsyncWebdav: public AsyncWebHandler {
     public:
-        AsyncWebdav(const String& url, fs::FS &fs);
+        typedef size_t (*quota_function)(void);
+
+    public:
+        AsyncWebdav(const String& url, fs::FS &fs, quota_function totalBytes = nullptr, quota_function usedBytes = nullptr);
 
         virtual bool canHandle(AsyncWebServerRequest *request) override final;
         virtual void handleRequest(AsyncWebServerRequest *request) override final;
@@ -20,6 +23,8 @@ class AsyncWebdav: public AsyncWebHandler {
     private:
         String _url;
         fs::FS _fs;
+        quota_function _totalBytes;
+        quota_function _usedBytes;
         void handlePropfind(const String& path, DavResourceType resource, AsyncWebServerRequest * request);
         void handleGet(const String& path, DavResourceType resource, AsyncWebServerRequest * request);
         void handlePut(const String& path, DavResourceType resource, AsyncWebServerRequest * request, unsigned char *data, size_t len, size_t index, size_t total);