diff --git a/src/corelib/io/qfilesystemwatcher_win_p.h b/src/corelib/io/qfilesystemwatcher_win_p.h
index 3678043351..79cec00c39 100644
--- a/src/corelib/io/qfilesystemwatcher_win_p.h
+++ b/src/corelib/io/qfilesystemwatcher_win_p.h
@@ -104,7 +104,10 @@ public:
 
 Q_DECLARE_TYPEINFO(QFileSystemWatcherPathKey, Q_RELOCATABLE_TYPE);
 
-inline size_t qHash(const QFileSystemWatcherPathKey &key) { return qHash(key.toCaseFolded()); }
+inline size_t qHash(const QFileSystemWatcherPathKey &key, size_t seed = 0)
+{
+    return qHash(key.toCaseFolded(), seed);
+}
 
 class QWindowsFileSystemWatcherEngineThread : public QThread
 {
diff --git a/src/gui/itemmodels/qfilesystemmodel_p.h b/src/gui/itemmodels/qfilesystemmodel_p.h
index 3cb08d1308..fa83208936 100644
--- a/src/gui/itemmodels/qfilesystemmodel_p.h
+++ b/src/gui/itemmodels/qfilesystemmodel_p.h
@@ -50,7 +50,10 @@ public:
 
 Q_DECLARE_TYPEINFO(QFileSystemModelNodePathKey, Q_RELOCATABLE_TYPE);
 
-inline size_t qHash(const QFileSystemModelNodePathKey &key) { return qHash(key.toCaseFolded()); }
+inline size_t qHash(const QFileSystemModelNodePathKey &key, size_t seed = 0)
+{
+    return qHash(key.toCaseFolded(), seed);
+}
 #else // Q_OS_WIN
 typedef QString QFileSystemModelNodePathKey;
 #endif