diff --git a/platformio.ini b/platformio.ini
index 01c9c04..57fcc59 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -30,7 +30,7 @@ lib_deps =
 extra_scripts = pre:extra_scripts.py
 
 [env:esp32dev]
-platform = espressif32
+platform = espressif32 @ 6.9.0
 board = esp32dev
 board_build.partitions = partitions_singleapp_large.csv
 framework = arduino
@@ -44,7 +44,7 @@ build_flags =
 lib_deps =
     makuna/NeoPixelBus@^2.7.6
     bblanchon/ArduinoJson@^6.17.2
-    links2004/WebSockets@2.4.1
+    links2004/WebSockets@^2.4.1
     adafruit/RTClib@^1.11.2
     knolleary/PubSubClient@^2.8.0
     https://github.com/tzapu/WiFiManager#v2.0.17
diff --git a/src/Wortuhr.cpp b/src/Wortuhr.cpp
index c2776fd..4b6f1ef 100644
--- a/src/Wortuhr.cpp
+++ b/src/Wortuhr.cpp
@@ -6,19 +6,20 @@
 #include <ESP8266WiFi.h>
 #include <ESP8266mDNS.h>
 #include <coredecls.h>
+#include <sntp.h>
 #elif defined(ESP32)
 #include <ESPmDNS.h>
 #include <HTTPUpdateServer.h>
 #include <Update.h>
 #include <WebServer.h>
 #include <WiFi.h>
+#include <esp_sntp.h>
 #endif
 #include <NeoPixelBus.h>
 #include <RTClib.h>
 #include <WiFiClient.h>
 #include <WiFiUdp.h>
 #include <Wire.h>
-#include <sntp.h>
 
 #include "Uhr.h"
 
@@ -89,20 +90,6 @@ uint16_t powerCycleCount = 0; // Variable to store power cycle count
 
 //------------------------------------------------------------------------------
 
-uint32_t sntp_startup_delay_MS_rfc_not_less_than_60000() {
-    if (externalRTC) {
-        Serial.println("SNTP startup delay 1min");
-        return 60000;
-    } else {
-        // yes this is against the RFC, but we don't have an RTC and want the
-        // time now.
-        Serial.println("no RTC clock - disable SNTP startup delay");
-        return 500;
-    }
-}
-
-//------------------------------------------------------------------------------
-
 void time_is_set() {
     time_t utc = time(nullptr);
     if (externalRTC) {