diff --git a/samples/combo/combo.cpp b/samples/combo/combo.cpp
index 6b5ced6c6e..51e8a869ce 100644
--- a/samples/combo/combo.cpp
+++ b/samples/combo/combo.cpp
@@ -557,6 +557,11 @@ public:
         }
     }
 
+    // Implement empty DoSetPopupControl to prevent assertion failure.
+    virtual void DoSetPopupControl(wxComboPopup* WXUNUSED(popup))
+    {
+    }
+
 private:
     void Init()
     {