diff --git a/src/libsync/utility.cpp b/src/libsync/utility.cpp
index 226fefee04..58c4815c71 100644
--- a/src/libsync/utility.cpp
+++ b/src/libsync/utility.cpp
@@ -557,8 +557,10 @@ void Utility::sortFilenames(QStringList& fileNames)
     collator.setNumericMode(true);
     collator.setCaseSensitivity(Qt::CaseInsensitive);
     qSort(fileNames.begin(), fileNames.end(), collator);
-#else
+#elif QT_VERSION >= QT_VERSION_CHECK(5, 0, 0)
     fileNames.sort(Qt::CaseInsensitive);
+#else
+    fileNames.sort();
 #endif
 }