diff --git a/src/kits/interface/InterfaceDefs.cpp b/src/kits/interface/InterfaceDefs.cpp
index df186d1a0f..b8e23a6ae6 100644
--- a/src/kits/interface/InterfaceDefs.cpp
+++ b/src/kits/interface/InterfaceDefs.cpp
@@ -730,7 +730,7 @@ ui_color(color_which which)
 				case B_FAILURE_COLOR:
 					return make_color(255,0,0);
 				default:
-					fprintf(stderr, "ui_color(): unknown color_which\n");
+					fprintf(stderr, "ui_color(): unknown color_which %d\n", which);
 					return make_color(0,0,0);
 			}
 	}