diff --git a/samples/widgets/slider.cpp b/samples/widgets/slider.cpp
index a30bacfa73..8f151f8b90 100644
--- a/samples/widgets/slider.cpp
+++ b/samples/widgets/slider.cpp
@@ -402,14 +402,14 @@ void SliderWidgetsPage::CreateSlider()
             break;
 
         case SliderTicks_Left:
-            flags |= wxSL_LEFT;
+            flags |= wxSL_LEFT | wxSL_VERTICAL;
             break;
 
         case SliderTicks_Bottom:
             flags |= wxSL_BOTTOM;
             break;
 
-        case SliderTicks_Right:
+        case SliderTicks_Right | wxSL_VERTICAL:
             flags |= wxSL_RIGHT;
             break;