diff --git a/contrib/tiflash-proxy-cmake/CMakeLists.txt b/contrib/tiflash-proxy-cmake/CMakeLists.txt
index 41c2d0bc4ab..5021782dfad 100644
--- a/contrib/tiflash-proxy-cmake/CMakeLists.txt
+++ b/contrib/tiflash-proxy-cmake/CMakeLists.txt
@@ -18,7 +18,7 @@ if(TIFLASH_LLVM_TOOLCHAIN AND USE_LIBCXX)
     if(LINKER_NAME)
         set(TIFLASH_RUSTFLAGS "-C link-arg=-fuse-ld=${LINKER_NAME} ${TIFLASH_RUSTFLAGS}")
     endif()
-    set(TIFLASH_RUST_ENV CXXSTDLIB=c++ CMAKE=${CMAKE_COMMAND} CFLAGS=-w CXXFLAGS=-w RUSTFLAGS=${TIFLASH_RUSTFLAGS})
+    set(TIFLASH_RUST_ENV CXXSTDLIB=c++ CMAKE=${CMAKE_COMMAND} CFLAGS=-w CXXFLAGS=-w RUSTFLAGS=${TIFLASH_RUSTFLAGS} PROTOC=${Protobuf_PROTOC_EXECUTABLE} PROTOC_INCLUDE=${Protobuf_INCLUDE_DIR})
     message(STATUS "enforce LLVM toolchain for rust: ${TIFLASH_RUST_ENV}")
 endif()