diff --git a/3rdparty/libsimpleio.cmake b/3rdparty/libsimpleio.cmake
index eb9d990d07..0844c9b1d8 100644
--- a/3rdparty/libsimpleio.cmake
+++ b/3rdparty/libsimpleio.cmake
@@ -38,4 +38,6 @@ target_include_directories(
   PUBLIC
     "${CMAKE_CURRENT_LIST_DIR}/libsimpleio/"
 )
+set_target_properties(simpleio PROPERTIES UNITY_BUILD 0)
+
 endif()