diff --git a/Code/Mantid/MantidQt/CustomInterfaces/src/MultiDatasetFit/MDFAddWorkspaceDialog.cpp b/Code/Mantid/MantidQt/CustomInterfaces/src/MultiDatasetFit/MDFAddWorkspaceDialog.cpp
index 034cd0bc993b04600e697665d0978733c5eea41a..c4bd1f1f3c62f85e240ab1fee44bdfd85d9668cc 100644
--- a/Code/Mantid/MantidQt/CustomInterfaces/src/MultiDatasetFit/MDFAddWorkspaceDialog.cpp
+++ b/Code/Mantid/MantidQt/CustomInterfaces/src/MultiDatasetFit/MDFAddWorkspaceDialog.cpp
@@ -16,7 +16,7 @@ namespace MDF
 
 /// Constructor.
 /// @param parent :: A parent widget.
-AddWorkspaceDialog::AddWorkspaceDialog(QWidget *parent):QDialog(parent)
+AddWorkspaceDialog::AddWorkspaceDialog(QWidget *parent):QDialog(parent),m_maxIndex(0)
 {
   m_uiForm.setupUi(this);
   // populate the combo box with names of eligible workspaces