diff --git a/include/wx/slider.h b/include/wx/slider.h
index 05e71cead5..84896602f9 100644
--- a/include/wx/slider.h
+++ b/include/wx/slider.h
@@ -40,7 +40,7 @@
 #define wxSL_INVERSE         0x1000
 #define wxSL_MIN_MAX_LABELS  0x2000
 #define wxSL_VALUE_LABEL     0x4000
-#define wxSL_LABELS          wxSL_MIN_MAX_LABELS|wxSL_VALUE_LABEL
+#define wxSL_LABELS          (wxSL_MIN_MAX_LABELS|wxSL_VALUE_LABEL)
 
 #if WXWIN_COMPATIBILITY_2_6
     // obsolete
diff --git a/interface/wx/slider.h b/interface/wx/slider.h
index d1fd50460e..f45c591804 100644
--- a/interface/wx/slider.h
+++ b/interface/wx/slider.h
@@ -24,11 +24,12 @@
     @style{wxSL_AUTOTICKS}
            Displays tick marks. Windows only.
     @style{wxSL_MIN_MAX_LABELS}
-           Displays minimum, maximum labels.
+           Displays minimum, maximum labels (new since wxWidgets 2.9.1).
     @style{wxSL_VALUE_LABEL}
-           Displays value label.
+           Displays value label (new since wxWidgets 2.9.1).
     @style{wxSL_LABELS}
-           Displays minimum, maximum and value labels (same as the two above together).
+           Displays minimum, maximum and value labels (same as wxSL_VALUE_LABEL
+           and wxSL_MIN_MAX_LABELS together).
     @style{wxSL_LEFT}
            Displays ticks on the left and forces the slider to be vertical.
     @style{wxSL_RIGHT}