Qt Creator doesn't use existing SOURCE/HEADER when adding new files

#-------------------------------------------------
#
# Project created by QtCreator 2012-11-24T19:28:11
#
#-------------------------------------------------

QT       += core gui

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = deeel
TEMPLATE = app


SOURCES += main.cpp\
        mainwindow.cpp

HEADERS  += mainwindow.h

FORMS    += mainwindow.ui

HEADERS += \
    test.h

SOURCES += \
    test.cpp

HEADERS += \
    othertest.h

SOURCES += \
    othertest.cpp

HEADERS += \
    lasttest.h

SOURCES += \
    lasttest.cpp