diff --git a/wled00/wled.cpp b/wled00/wled.cpp
index 588b8737..02287064 100644
--- a/wled00/wled.cpp
+++ b/wled00/wled.cpp
@@ -479,8 +479,10 @@ void WLED::setup()
   #ifdef ARDUINO_ARCH_ESP32
   busDrawMux = xSemaphoreCreateRecursiveMutex();       // WLEDMM prevent concurrent running of strip.show and strip.service
   segmentMux = xSemaphoreCreateRecursiveMutex();       // WLEDMM prevent segment changes while effects are running
+  jsonBufferLockMutex = xSemaphoreCreateRecursiveMutex(); // WLEDMM prevent concurrent JSON buffer writing
   xSemaphoreGiveRecursive(busDrawMux);                 // init semaphores to initially allow drawing
   xSemaphoreGiveRecursive(segmentMux);
+  xSemaphoreGiveRecursive(jsonBufferLockMutex);
   #endif
 
   #ifdef ARDUINO_ARCH_ESP32
diff --git a/wled00/wled.h b/wled00/wled.h
index e947514d..f3abbb7d 100644
--- a/wled00/wled.h
+++ b/wled00/wled.h
@@ -770,6 +770,7 @@ WLED_GLOBAL volatile bool OTAisRunning _INIT(false);        // WLEDMM temporaril
 #ifdef ARDUINO_ARCH_ESP32
 WLED_GLOBAL SemaphoreHandle_t busDrawMux _INIT(nullptr);
 WLED_GLOBAL SemaphoreHandle_t segmentMux _INIT(nullptr);
+WLED_GLOBAL SemaphoreHandle_t jsonBufferLockMutex _INIT(nullptr);
 #define esp32SemTake(mux,timeout) xSemaphoreTakeRecursive(mux, timeout) // convenience macro that expands to xSemaphoreTakeRecursive
 #define esp32SemGive(mux)  xSemaphoreGiveRecursive(mux)                 // convenience macro that expands to xSemaphoreGiveRecursive
 #define WLED_create_spinlock(theSname) static portMUX_TYPE theSname = portMUX_INITIALIZER_UNLOCKED