--- /dev/null
+diff --git a/cmake/OpenCVDownload.cmake b/cmake/OpenCVDownload.cmake
+index 63cf6d3..01e84a5 100644
+--- a/cmake/OpenCVDownload.cmake
++++ b/cmake/OpenCVDownload.cmake
+@@ -157,6 +157,9 @@ function(ocv_download)
+ # Download
+ if(NOT EXISTS "${CACHE_CANDIDATE}")
+ ocv_download_log("#cmake_download \"${CACHE_CANDIDATE}\" \"${DL_URL}\"")
++ string(REPLACE "${OPENCV_DOWNLOAD_PATH}/" "opencv-cache/" CACHE_SUBPATH "${CACHE_CANDIDATE}")
++ message(FATAL_ERROR " Downloads are not permitted during configure. Please pre-download the file \"${CACHE_CANDIDATE}\":\n \n vcpkg_download_distfile(OCV_DOWNLOAD\n URLS \"${DL_URL}\"\n FILENAME \"${CACHE_SUBPATH}\"\n SHA512 0\n )")
++
+ foreach(try ${OPENCV_DOWNLOAD_TRIES_LIST})
+ ocv_download_log("#try ${try}")
+ file(DOWNLOAD "${DL_URL}" "${CACHE_CANDIDATE}"