diff --git a/wled00/wled_server.cpp b/wled00/wled_server.cpp
index 626c2708..9775da24 100644
--- a/wled00/wled_server.cpp
+++ b/wled00/wled_server.cpp
@@ -37,10 +37,15 @@ void handleUpload(AsyncWebServerRequest *request, const String& filename, size_t
     return;
   }
   if (!index) {
-    request->_tempFile = WLED_FS.open(filename, "w");
+    String finalname = filename;
+    if (finalname.charAt(0) != '/') {
+      finalname = "/" + finalname; // prepend slash if missing
+    }
+
+    request->_tempFile = WLED_FS.open(finalname, "w");
     DEBUG_PRINT("Uploading ");
-    DEBUG_PRINTLN(filename);
-    if (filename == F("/presets.json")) presetsModifiedTime = toki.second();
+    DEBUG_PRINTLN(finalname);
+    if (finalname == "/presets.json") presetsModifiedTime = toki.second();
   }
   if (len) {
     request->_tempFile.write(data,len);