diff --git a/cmake/external/protobuf.cmake b/cmake/external/protobuf.cmake
index c5dc5bee619995b2ee3e3689fd8a488f7cd42507..3e417f123b5f668988c6469f76ae6dc3caa421f6 100644
--- a/cmake/external/protobuf.cmake
+++ b/cmake/external/protobuf.cmake
@@ -18,7 +18,7 @@ FUNCTION(build_protobuf TARGET_NAME BUILD_FOR_HOST)
     SET(PROTOBUF_SOURCES_DIR ${THIRD_PARTY_PATH}/${TARGET_NAME})
     SET(PROTOBUF_INSTALL_DIR ${THIRD_PARTY_PATH}/install/${TARGET_NAME})
 
-    SET(${TARGET_NAME}_INCLUDE_DIR "${PROTOBUF_INSTALL_DIR}/include")
+    SET(${TARGET_NAME}_INCLUDE_DIR "${PROTOBUF_INSTALL_DIR}/include" PARENT_SCOPE)
     SET(PROTOBUF_INCLUDE_DIR "${PROTOBUF_INSTALL_DIR}/include" PARENT_SCOPE)
     SET(${TARGET_NAME}_LITE_LIBRARY
         "${PROTOBUF_INSTALL_DIR}/lib/libprotobuf-lite${STATIC_LIBRARY_SUFFIX}"