diff --git a/tests/auto/ioutils/ioutils.pro b/tests/auto/ioutils/ioutils.pro
index 960183d79e316eca79e495cc8b74c92fafab01cd..1e2f7d1af23a6c2b3732f30939f29ad871e76aa5 100644
--- a/tests/auto/ioutils/ioutils.pro
+++ b/tests/auto/ioutils/ioutils.pro
@@ -1,6 +1,7 @@
 include(../qttest.pri)
 
-DEFINES += QT_BOOTSTRAPPED # for shellQuote(). hopefully without side effects ...
+# for shellQuote(). hopefully without side effects ...
+isEqual(QT_MAJOR_VERSION, 4):DEFINES += QT_BOOTSTRAPPED
 INCLUDEPATH += $$IDE_SOURCE_TREE/src/shared
 SOURCES += tst_ioutils.cpp \
     $$IDE_SOURCE_TREE/src/shared/proparser/ioutils.cpp