diff --git a/autotests/jobtest.h b/autotests/jobtest.h
--- a/autotests/jobtest.h
+++ b/autotests/jobtest.h
@@ -84,6 +84,9 @@
 #endif
     void mostLocalUrl();
     void chmodFile();
+#ifdef Q_OS_UNIX
+    void chmodSticky();
+#endif
     void chmodFileError();
     void mimeType();
     void mimeTypeError();
diff --git a/autotests/jobtest.cpp b/autotests/jobtest.cpp
--- a/autotests/jobtest.cpp
+++ b/autotests/jobtest.cpp
@@ -1473,6 +1473,26 @@
     QFile::remove(filePath);
 }
 
+#ifdef Q_OS_UNIX
+void JobTest::chmodSticky()
+{
+    const QString filePath = homeTmpDir() + "fileForChmodSticky";
+    createTestFile(filePath);
+    KFileItem item(QUrl::fromLocalFile(filePath));
+    const mode_t origPerm = item.permissions();
+    mode_t newPerm = origPerm ^ S_ISVTX;
+    QVERIFY(newPerm != origPerm);
+    KFileItemList items({item});
+    KIO::Job *job = KIO::chmod(items, newPerm, S_ISVTX, QString(), QString(), false, KIO::HideProgressInfo);
+    job->setUiDelegate(nullptr);
+    QVERIFY(job->exec());
+
+    KFileItem newItem(QUrl::fromLocalFile(filePath));
+    QCOMPARE(QString::number(newItem.permissions(), 8), QString::number(newPerm, 8));
+    QFile::remove(filePath);
+}
+#endif
+
 void JobTest::chmodFileError()
 {
     // chown(root) should fail
diff --git a/src/ioslaves/file/file.cpp b/src/ioslaves/file/file.cpp
--- a/src/ioslaves/file/file.cpp
+++ b/src/ioslaves/file/file.cpp
@@ -225,7 +225,12 @@
     const QString path(url.toLocalFile());
     const QByteArray _path(QFile::encodeName(path));
     /* FIXME: Should be atomic */
+#ifdef Q_OS_UNIX
+    // QFile::Permissions does not support special attributes like sticky
+    if (::chmod(QFile::encodeName(path).constData(), permissions) == -1 ||
+#else
     if (!QFile::setPermissions(path, modeToQFilePermissions(permissions)) ||
+#endif
             (setACL(_path.data(), permissions, false) == -1) ||
             /* if not a directory, cannot set default ACLs */
             (setACL(_path.data(), permissions, true) == -1 && errno != ENOTDIR)) {