diff --git a/runtime/Cpp/runtime/CMakeLists.txt b/runtime/Cpp/runtime/CMakeLists.txt
index 86fdab9..97486fb 100644
--- a/runtime/Cpp/runtime/CMakeLists.txt
+++ b/runtime/Cpp/runtime/CMakeLists.txt
@@ -120,7 +120,7 @@ set(static_lib_suffix "")
 if (WIN32)
   set(static_lib_suffix "-static")
   if (TARGET antlr4_shared)
-    target_compile_definitions(antlr4_shared PUBLIC ANTLR4CPP_EXPORTS)
+    target_compile_definitions(antlr4_shared PRIVATE ANTLR4CPP_EXPORTS)
   endif()
   if (TARGET antlr4_static)
     target_compile_definitions(antlr4_static PUBLIC ANTLR4CPP_STATIC)