diff --git a/qbs/defaults.js b/qbs/defaults.js
index 7c11a2c0adb..2233af0995d 100644
--- a/qbs/defaults.js
+++ b/qbs/defaults.js
@@ -7,7 +7,8 @@ function defines(qbs)
 {
     var list = [
         'IDE_LIBRARY_BASENAME="lib"',
-        "QT_DISABLE_DEPRECATED_BEFORE=0x040900"
+        "QT_DISABLE_DEPRECATED_BEFORE=0x040900",
+        "QT_NO_CAST_TO_ASCII"
     ]
     if (testsEnabled(qbs))
         list.push("WITH_TESTS")