diff --git a/WINGs/wfontpanel.c b/WINGs/wfontpanel.c
index 537e54dd..c03a7792 100644
--- a/WINGs/wfontpanel.c
+++ b/WINGs/wfontpanel.c
@@ -585,7 +585,7 @@ listFamilies(WMScreen *scr, WMFontPanel *panel)
     int i;
 
     pat = FcPatternCreate();
-    os = FcObjectSetBuild(FC_FAMILY, FC_STYLE, 0);
+    os = FcObjectSetBuild(FC_FAMILY, FC_STYLE, NULL);
     fs = FcFontList(0, pat, os);
     if (!fs) {
         WMRunAlertPanel(scr, panel->win, _("Error"),