diff --git a/wled00/json.cpp b/wled00/json.cpp
index 444f0e4d..f672f53d 100644
--- a/wled00/json.cpp
+++ b/wled00/json.cpp
@@ -1397,9 +1397,9 @@ void serializeNodes(JsonObject root)
 // deserializes mode data string into JsonArray
 void serializeModeData(JsonArray fxdata)
 {
-  char lineBuffer[128];
+  char lineBuffer[192] = { 0 };
   for (size_t i = 0; i < strip.getModeCount(); i++) {
-    strncpy_P(lineBuffer, strip.getModeData(i), 127);
+    strncpy_P(lineBuffer, strip.getModeData(i), sizeof(lineBuffer)-1);
     if (lineBuffer[0] != 0) {
       char* dataPtr = strchr(lineBuffer,'@');
       if (dataPtr) fxdata.add(dataPtr+1);
@@ -1411,9 +1411,9 @@ void serializeModeData(JsonArray fxdata)
 // deserializes mode names string into JsonArray
 // also removes effect data extensions (@...) from deserialized names
 void serializeModeNames(JsonArray arr) {
-  char lineBuffer[128];
+  char lineBuffer[192] = { 0 };
   for (size_t i = 0; i < strip.getModeCount(); i++) {
-    strncpy_P(lineBuffer, strip.getModeData(i), 127);
+    strncpy_P(lineBuffer, strip.getModeData(i), sizeof(lineBuffer)-1);
     if (lineBuffer[0] != 0) {
       char* dataPtr = strchr(lineBuffer,'@');
       if (dataPtr) *dataPtr = 0; // terminate mode data after name