diff --git a/docs/index.md b/docs/index.md
index 8b213e8..9cf1e0e 100644
--- a/docs/index.md
+++ b/docs/index.md
@@ -15,7 +15,6 @@ This fork is based on https://github.com/yubox-node-org/ESPAsyncWebServer and in
 - Deployed in PlatformIO registry and Arduino IDE library manager
 - CI
 - Only supports ESP32
-- Resurrected `AsyncWebSocketMessageBuffer` and `makeBuffer()` in order to make the fork API-compatible with the original library from me-no-dev regarding WebSocket.
 
 ## Documentation
 
@@ -24,29 +23,13 @@ Please look at the original libraries for more examples and documentation.
 
 [https://github.com/yubox-node-org/ESPAsyncWebServer](https://github.com/yubox-node-org/ESPAsyncWebServer)
 
-## `AsyncWebSocketMessageBuffer` and `makeBuffer()`
+## Pitfalls
 
-The fork from `yubox-node-org` introduces some breaking API changes compared to the original library, especially regarding the use of `std::shared_ptr<std::vector<uint8_t>>` for WebSocket.
+The fork from yubox introduces some breaking API changes compared to the original library, especially regarding the use of `std::shared_ptr<std::vector<uint8_t>>` for WebSocket.
+Thanks to this fork, you can handle them by using `ASYNCWEBSERVER_FORK_mathieucarbou`.
 
-This fork is compatible with the original library from `me-no-dev` regarding WebSocket, and wraps the optimizations done by `yubox-node-org` in the `AsyncWebSocketMessageBuffer` class.
-So you have the choice of which API to use.
-I strongly suggest to use the optimized API from `yubox-node-org` as it is much more efficient.
-
-Here is an example for serializing a Json document in a websocket message buffer. This code is compatible with any forks, but not optimized:
-
-```cpp
-void send(JsonDocument& doc) {
-  const size_t len = measureJson(doc);
-  
-  // original API from me-no-dev
-  AsyncWebSocketMessageBuffer* buffer = _ws->makeBuffer(len);
-  assert(buffer); // up to you to keep or remove this
-  serializeJson(doc, buffer->get(), len);
-  _ws->textAll(buffer);
-}
-```
-
-Here is an example for serializing a Json document in a more optimized way, and compatible with both forks:
+Here is an example for serializing a Json document in a websocket message buffer directly.
+This code is compatible with both forks.
 
 ```cpp
 void send(JsonDocument& doc) {
diff --git a/library.json_ b/library.json
similarity index 97%
rename from library.json_
rename to library.json
index 94271bd..1730ad5 100644
--- a/library.json_
+++ b/library.json
@@ -1,6 +1,6 @@
 {
   "name": "ESP Async WebServer",
-  "version": "2.6.1",
+  "version": "2.5.1",
   "description": "Asynchronous HTTP and WebSocket Server Library for ESP32. Supports: WebSocket, SSE, Authentication, Arduino Json 7, File Upload, Static File serving, URL Rewrite, URL Redirect, etc.",
   "keywords": "http,async,websocket,webserver",
   "homepage": "https://github.com/mathieucarbou/ESPAsyncWebServer",
diff --git a/library.properties b/library.properties
index fda5f3f..2e5699f 100644
--- a/library.properties
+++ b/library.properties
@@ -1,5 +1,5 @@
 name=ESP Async WebServer
-version=2.6.1
+version=2.5.1
 author=Me-No-Dev
 maintainer=Mathieu Carbou <mathieu.carbou@gmail.com>
 sentence=Asynchronous HTTP and WebSocket Server Library for ESP32
diff --git a/src/AsyncWebSocket.cpp b/src/AsyncWebSocket.cpp
index 90f14cd..75189cf 100644
--- a/src/AsyncWebSocket.cpp
+++ b/src/AsyncWebSocket.cpp
@@ -798,7 +798,7 @@ void AsyncWebSocketClient::binary(const __FlashStringHelper *data, size_t len)
 IPAddress AsyncWebSocketClient::remoteIP() const
 {
     if (!_client)
-        return IPAddress((uint32_t)0U);
+        return {}; // IPAddress(0U);
 
     return _client->remoteIP();
 }
diff --git a/src/ESPAsyncWebServer.h b/src/ESPAsyncWebServer.h
index 8955c39..2c88bda 100644
--- a/src/ESPAsyncWebServer.h
+++ b/src/ESPAsyncWebServer.h
@@ -40,9 +40,9 @@
 #error Platform not supported
 #endif
 
-#define ASYNCWEBSERVER_VERSION "2.6.1"
+#define ASYNCWEBSERVER_VERSION "2.5.1"
 #define ASYNCWEBSERVER_VERSION_MAJOR 2
-#define ASYNCWEBSERVER_VERSION_MINOR 6
+#define ASYNCWEBSERVER_VERSION_MINOR 5
 #define ASYNCWEBSERVER_VERSION_REVISION 1
 #define ASYNCWEBSERVER_FORK_mathieucarbou
 
diff --git a/src/WebHandlers.cpp b/src/WebHandlers.cpp
index 0b55b0d..c79cdbb 100644
--- a/src/WebHandlers.cpp
+++ b/src/WebHandlers.cpp
@@ -58,7 +58,7 @@ AsyncStaticWebHandler& AsyncStaticWebHandler::setCacheControl(const char* cache_
 }
 
 AsyncStaticWebHandler& AsyncStaticWebHandler::setLastModified(const char* last_modified){
-  _last_modified = last_modified;
+  _last_modified = String(last_modified);
   return *this;
 }
 
@@ -205,9 +205,7 @@ void AsyncStaticWebHandler::handleRequest(AsyncWebServerRequest *request)
       return request->requestAuthentication();
 
   if (request->_tempFile == true) {
-    time_t lw = request->_tempFile.getLastWrite();    // get last file mod time (if supported by FS)
-    if (lw) setLastModified(gmtime(&lw));
-    String etag(lw ? lw : request->_tempFile.size());   // set etag to lastmod timestamp if available, otherwise to size
+    String etag = String(request->_tempFile.size());
     if (_last_modified.length() && _last_modified == request->header(F("If-Modified-Since"))) {
       request->_tempFile.close();
       request->send(304); // Not modified