diff --git a/src/common/list.cpp b/src/common/list.cpp
index 9c5603a0fa..28f4148c7b 100644
--- a/src/common/list.cpp
+++ b/src/common/list.cpp
@@ -762,7 +762,7 @@ wxNode *wxStringList::Prepend(const wxChar *s)
     WX_DEFINE_LIST(wxObjectList);
 
 // with wxUSE_STL wxStringList contains wxString objects, not pointers
-void wxStringListBase::DeleteFunction( const wxString X )
+void wxStringListBase::DeleteFunction( const wxString WXUNUSED(X) )
 {
 }