diff --git a/simple64-input-qt/CMakeLists.txt b/simple64-input-qt/CMakeLists.txt
index 737947e..fe27e81 100644
--- a/simple64-input-qt/CMakeLists.txt
+++ b/simple64-input-qt/CMakeLists.txt
@@ -40,6 +40,9 @@ if (UNIX)
     )
 endif (UNIX)
 
+set_property(TARGET simple64-input-qt PROPERTY C_VISIBILITY_PRESET hidden)
+set_property(TARGET simple64-input-qt PROPERTY CXX_VISIBILITY_PRESET hidden)
+set_property(TARGET simple64-input-qt PROPERTY VISIBILITY_INLINES_HIDDEN ON)
 set_target_properties(simple64-input-qt PROPERTIES PREFIX "")
 target_compile_options(simple64-input-qt PRIVATE -march=x86-64-v3)
 target_link_options(simple64-input-qt PRIVATE -march=x86-64-v3)