diff --git a/library/library.pro b/library/library.pro
index 2a3a5d7..52a8881 100644
--- a/library/library.pro
+++ b/library/library.pro
@@ -9,7 +9,7 @@ INCLUDEPATH += $$_PRO_FILE_PWD_/include/mobilisis
 INCLUDEPATH += $$_PRO_FILE_PWD_/include/rapidjson
 
 win32 {
-CONFIG+=-DCALCULATE_LIBRARY_EXPORTS
+QMAKE_CXXFLAGS += -DCALCULATE_LIBRARY_EXPORTS
 }
 
 SOURCES += \