diff --git a/app/src/main/cpp/PhoneDevice.cpp b/app/src/main/cpp/PhoneDevice.cpp
index b2185b11..b918767f 100644
--- a/app/src/main/cpp/PhoneDevice.cpp
+++ b/app/src/main/cpp/PhoneDevice.cpp
@@ -1593,7 +1593,7 @@ bool CPhoneDevice::OnImageReady(cv::Mat& mat)
         {
             shouldRetry = true;
             // replaceAll(fullPath, ".jpg", std::string("-") + std::to_string(mPhotoInfo.retries) + ".jpg");
-            replaceAll(fullPath, "_FF_", std::to_string(mPhotoInfo.retries));
+            replaceAll(fullPath, "_FF_", std::string("_") + std::to_string(mPhotoInfo.retries) + std::string("_"));
             XYLOG(XYLOG_SEVERITY_ERROR, "Photo is TOO dark or light(LDR=%u), will RETRY it", (uint32_t)captureResult.avgY);
         }