diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4edee36..0806f5a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -50,7 +50,10 @@ target_link_libraries(camera_to_rtsp
 
 # 运行时把 config.json 复制到 bin/ 目录
 add_custom_command(TARGET camera_to_rtsp POST_BUILD
-    COMMAND ${CMAKE_COMMAND} -E copy_if_different
-    ${CMAKE_SOURCE_DIR}/config.json
-    $<TARGET_FILE_DIR:camera_to_rtsp>/config.json
+    COMMAND ${CMAKE_COMMAND} -E echo "Checking config.json..."
+    COMMAND ${CMAKE_COMMAND} -E test -e $<TARGET_FILE_DIR:camera_to_rtsp>/config.json
+        || ${CMAKE_COMMAND} -E copy
+            ${CMAKE_SOURCE_DIR}/config.json
+            $<TARGET_FILE_DIR:camera_to_rtsp>/config.json
 )
+