diff --git a/src/lay/lay/layMacroEditorDialog.cc b/src/lay/lay/layMacroEditorDialog.cc
index 7573154e0..ac46f6402 100644
--- a/src/lay/lay/layMacroEditorDialog.cc
+++ b/src/lay/lay/layMacroEditorDialog.cc
@@ -1890,7 +1890,7 @@ MacroEditorDialog::set_editor_focus ()
     return;
   }
 
-  QSignalBlocker signal_blocker (searchEditBox);
+  lay::SignalBlocker signal_blocker (searchEditBox);
   page->set_editor_focus ();
 }
 
diff --git a/src/lay/lay/layMacroEditorPage.cc b/src/lay/lay/layMacroEditorPage.cc
index 0eb04be59..3cdd98a78 100644
--- a/src/lay/lay/layMacroEditorPage.cc
+++ b/src/lay/lay/layMacroEditorPage.cc
@@ -43,7 +43,6 @@
 #include <QResource>
 #include <QBuffer>
 #include <QTimer>
-#include <QWindow>
 #include <QListWidget>
 #include <QApplication>
 
diff --git a/src/laybasic/laybasic/layQtTools.cc b/src/laybasic/laybasic/layQtTools.cc
index bc7a1e537..a769a07be 100644
--- a/src/laybasic/laybasic/layQtTools.cc
+++ b/src/laybasic/laybasic/layQtTools.cc
@@ -189,5 +189,21 @@ indicate_error (QWidget *le, bool f)
   le->setPalette (pl);
 }
 
+#if QT_VERSION < 0x050000
+
+SignalBlocker::SignalBlocker (QWidget *w)
+  : mp_widget (w)
+{
+  m_state = mp_widget->blockSignals (true);
+}
+
+SignalBlocker::~SignalBlocker ()
+{
+  mp_widget->blockSignals (m_state);
+}
+
+#endif
+
+
 }
 
diff --git a/src/laybasic/laybasic/layQtTools.h b/src/laybasic/laybasic/layQtTools.h
index fc11d89ee..36a02b368 100644
--- a/src/laybasic/laybasic/layQtTools.h
+++ b/src/laybasic/laybasic/layQtTools.h
@@ -31,6 +31,7 @@
 class QLabel;
 class QWidget;
 class QObject;
+class QSignalBlocker;
 
 namespace tl
 {
@@ -81,6 +82,27 @@ LAYBASIC_PUBLIC void indicate_error (QWidget *le, const tl::Exception *ex);
  */
 LAYBASIC_PUBLIC void indicate_error (QWidget *le, bool error);
 
+#if QT_VERSION < 0x050000
+
+//  Provide missing QSignalBlocker for Qt4
+
+class SignalBlocker
+{
+public:
+  SignalBlocker (QWidget *w);
+  ~SignalBlocker ();
+
+private:
+  QWidget *mp_widget;
+  bool m_state;
+};
+
+#else
+
+typedef QSignalBlocker SignalBlocker;
+
+#endif
+
 } // namespace lay
 
 #endif