diff --git a/CMakeLists.txt b/CMakeLists.txt
index 89b75ca..f81d254 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -67,6 +67,12 @@ else()
 set(MULTI_THREADED_VAL true)
 endif()
 
+if(DEFINED ADD_USER_OPEN)
+set(ADD_USER_OPEN_VAL ${ADD_USER_OPEN})
+else()
+set(ADD_USER_OPEN_VAL true)
+endif()
+
 if(DEFINED RETURN_ON_DEL_NAME)
 set(RETURN_ON_DEL_VAL true)
 set(RETURN_ON_DEL_NAME_VAL "\"" + ${RETURN_ON_DEL_NAME} + "\"")