diff --git a/src/qt/choice.cpp b/src/qt/choice.cpp
index aafaee9920..43eb30c5d3 100644
--- a/src/qt/choice.cpp
+++ b/src/qt/choice.cpp
@@ -161,6 +161,8 @@ unsigned wxChoice::GetCount() const
 
 wxString wxChoice::GetString(unsigned int n) const
 {
+    wxCHECK_MSG(n < GetCount(), wxString(), "invalid index");
+
     return wxQtConvertString( m_qtComboBox->itemText(n) );
 }