diff --git a/3rdparty/interface/process/kptyprocess.cpp b/3rdparty/interface/process/kptyprocess.cpp
index f200cb84..0a61e374 100644
--- a/3rdparty/interface/process/kptyprocess.cpp
+++ b/3rdparty/interface/process/kptyprocess.cpp
@@ -46,9 +46,11 @@ KPtyProcess::KPtyProcess(QObject *parent) :
     d->pty->open();
     connect(this, SIGNAL(stateChanged(QProcess::ProcessState)),
             SLOT(_k_onStateChanged(QProcess::ProcessState)));
+#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
     setChildProcessModifier([this](){
         setupChildProcessImpl();
     });
+#endif
 }
 
 KPtyProcess::KPtyProcess(int ptyMasterFd, QObject *parent) :
@@ -60,9 +62,11 @@ KPtyProcess::KPtyProcess(int ptyMasterFd, QObject *parent) :
     d->pty->open(ptyMasterFd);
     connect(this, SIGNAL(stateChanged(QProcess::ProcessState)),
             SLOT(_k_onStateChanged(QProcess::ProcessState)));
+#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
     setChildProcessModifier([this](){
         setupChildProcessImpl();
     });
+#endif
 }
 
 KPtyProcess::~KPtyProcess()
diff --git a/src/source/tree/treeheaderview.cpp b/src/source/tree/treeheaderview.cpp
index 93c2bceb..c5031b04 100644
--- a/src/source/tree/treeheaderview.cpp
+++ b/src/source/tree/treeheaderview.cpp
@@ -95,7 +95,11 @@ void PreviousLabel::mouseDoubleClickEvent(QMouseEvent *event)
     QLabel::mouseDoubleClickEvent(event);
 }
 
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
+void PreviousLabel::enterEvent(QEvent *event)
+#else
 void PreviousLabel::enterEvent(QEnterEvent *event)
+#endif
 {
     // qDebug() << "PreviousLabel enter event";
     if(!hasFocus()) {
diff --git a/src/source/tree/treeheaderview.h b/src/source/tree/treeheaderview.h
index 911ef97b..1dd8d3b8 100644
--- a/src/source/tree/treeheaderview.h
+++ b/src/source/tree/treeheaderview.h
@@ -46,7 +46,11 @@ class PreviousLabel: public Dtk::Widget::DLabel
 protected:
     void paintEvent(QPaintEvent *e) override;
     void mouseDoubleClickEvent(QMouseEvent *event) override;
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
+    void enterEvent(QEvent *event) override;
+#else
     void enterEvent(EnterEvent *event) override;
+#endif
     void leaveEvent(QEvent *event) override;
     void focusInEvent(QFocusEvent *event) Q_DECL_OVERRIDE;
     void focusOutEvent(QFocusEvent *event) Q_DECL_OVERRIDE;