diff --git a/cmake/OpenCVDetectCXXCompiler.cmake b/cmake/OpenCVDetectCXXCompiler.cmake
index c65081ca7a..7b0d4c30bf 100644
--- a/cmake/OpenCVDetectCXXCompiler.cmake
+++ b/cmake/OpenCVDetectCXXCompiler.cmake
@@ -114,6 +114,8 @@ if(MSVC)
     set(OpenCV_RUNTIME vc14)
   elseif(MSVC_VERSION EQUAL 1910 OR MSVC_VERSION EQUAL 1911)
     set(OpenCV_RUNTIME vc15)
+  else()
+    message(WARNING "OpenCV does not recognize MSVC_VERSION \"${MSVC_VERSION}\". Cannot set OpenCV_RUNTIME")
   endif()
 elseif(MINGW)
   set(OpenCV_RUNTIME mingw)