--- 3rdparty/protobuf/CMakeLists.txt.orig	2020-12-20 16:15:49.000000000 -0600
+++ 3rdparty/protobuf/CMakeLists.txt	2020-12-23 18:53:09.000000000 -0600
@@ -142,7 +142,7 @@
 
 include_directories(BEFORE "${PROTOBUF_ROOT}/src")  # ensure using if own headers: https://github.com/opencv/opencv/issues/13328
 add_library(libprotobuf STATIC ${OPENCV_3RDPARTY_EXCLUDE_FROM_ALL} ${Protobuf_SRCS})
-target_include_directories(libprotobuf SYSTEM PUBLIC $<BUILD_INTERFACE:${PROTOBUF_ROOT}/src>)
+target_include_directories(libprotobuf PUBLIC $<BUILD_INTERFACE:${PROTOBUF_ROOT}/src>)
 set_target_properties(libprotobuf
     PROPERTIES
     FOLDER "3rdparty"