diff --git a/tests/auto/corelib/io/qfileinfo/tst_qfileinfo.cpp b/tests/auto/corelib/io/qfileinfo/tst_qfileinfo.cpp
index 563e4c2a83..fbc21d7a05 100644
--- a/tests/auto/corelib/io/qfileinfo/tst_qfileinfo.cpp
+++ b/tests/auto/corelib/io/qfileinfo/tst_qfileinfo.cpp
@@ -1905,9 +1905,24 @@ void tst_QFileInfo::isWritable()
     tempfile.write("This file is generated by the QFileInfo autotest.");
     tempfile.close();
 
+    // isWritable returns true when file is writable
     QVERIFY(QFileInfo("tempfile.txt").isWritable());
+
+    QFile::setPermissions("tempfile.txt",
+                          QFileDevice::ReadOwner | QFileDevice::ReadUser | QFileDevice::ReadGroup);
+
+    // isWritable returns false when read-only, unless root
+    bool isRoot = false;
+#if defined (Q_OS_UNIX)
+    isRoot = (geteuid() == 0);
+#endif
+    QCOMPARE(QFileInfo("tempfile.txt").isWritable(), isRoot);
+
     tempfile.remove();
 
+    // isWritable returns false when file does not exist
+    QVERIFY(!QFileInfo("tempfile.txt").isWritable());
+
 #if defined(Q_OS_WIN)
     QFileInfo fi("c:\\pagefile.sys");
     QVERIFY2(fi.exists(), msgDoesNotExist(fi.absoluteFilePath()).constData());