diff --git a/lib/framework/UploadFileService.cpp b/lib/framework/UploadFileService.cpp
index c609048b0..c78be7fda 100644
--- a/lib/framework/UploadFileService.cpp
+++ b/lib/framework/UploadFileService.cpp
@@ -43,22 +43,23 @@ void UploadFileService::handleUpload(AsyncWebServerRequest * request, const Stri
         }
 
         if (is_firmware) {
+            // Check firmware header, 0xE9 magic offset 0 indicates esp bin, chip offset 12: esp32:0, S2:2, C3:5
 #if CONFIG_IDF_TARGET_ESP32 // ESP32/PICO-D4
             bool isC3 = (fname.find("C3") != std::string::npos);
             bool isS2 = (fname.find("S2") != std::string::npos);
-            if (isC3 || isS2) {
+            if (isC3 || isS2 || (len > 12 && (data[0] != 0xE9 || data[12] != 0))) {
                 handleError(request, 503); // service unavailable
                 return;
             }
 #elif CONFIG_IDF_TARGET_ESP32S2
             bool isS2 = (fname.find("S2") != std::string::npos);
-            if (!isS2) {
+            if (!isS2 || (len > 12 && (data[0] != 0xE9 || data[12] != 2))) {
                 handleError(request, 503); // service unavailable
                 return;
             }
 #elif CONFIG_IDF_TARGET_ESP32C3
             bool isC3 = (fname.find("C3") != std::string::npos);
-            if (!isC3) {
+            if (!isC3 || (len > 12 && (data[0] != 0xE9 || data[12] != 5))) {
                 handleError(request, 503); // service unavailable
                 return;
             }