diff --git a/src/gui.c b/src/gui.c
index 8f4b896ee..99f1603c9 100644
--- a/src/gui.c
+++ b/src/gui.c
@@ -573,7 +573,7 @@ static int guiUIUpdater(int modified)
         diaGetInt(diaUIConfig, UICFG_THEME, &temp);
         if (temp != curTheme) {
             curTheme = temp;
-            if (temp == 0) {
+            if (IS_DEFAULT_THEME(temp)) {
                 // Display the default theme's colours.
                 diaSetItemType(diaUIConfig, UICFG_BGCOL, UI_COLOUR); // Must be correctly set before doing the diaS/GetColor !!
                 diaSetItemType(diaUIConfig, UICFG_UICOL, UI_COLOUR);