diff --git a/MantidQt/CustomInterfaces/src/EnggDiffraction/EnggDiffractionViewQtGUI.cpp b/MantidQt/CustomInterfaces/src/EnggDiffraction/EnggDiffractionViewQtGUI.cpp
index 4212facebb646eb5d829dfda6ff8f5ab99a8089f..bb815146a0476f3a677e6aa416c91d41f08aaa14 100644
--- a/MantidQt/CustomInterfaces/src/EnggDiffraction/EnggDiffractionViewQtGUI.cpp
+++ b/MantidQt/CustomInterfaces/src/EnggDiffraction/EnggDiffractionViewQtGUI.cpp
@@ -331,8 +331,10 @@ void EnggDiffractionViewQtGUI::doSetupGeneralWidgets() {
   connect(m_ui.pushButton_help, SIGNAL(released()), this, SLOT(openHelpWin()));
   // note connection to the parent window, otherwise an empty frame window
   // may remain open and visible after this close
-  connect(m_ui.pushButton_close, SIGNAL(released()), this->parent(),
-          SLOT(close()));
+  if(this->parent()) {
+    connect(m_ui.pushButton_close, SIGNAL(released()), this->parent(),
+            SLOT(close()));
+  }
 
   connect(m_ui.lineEdit_RBNumber, SIGNAL(editingFinished()), this,
           SLOT(RBNumberChanged()));