diff --git a/src/as/com/threerings/util/Util.as b/src/as/com/threerings/util/Util.as
index be0f647a5..978282b65 100644
--- a/src/as/com/threerings/util/Util.as
+++ b/src/as/com/threerings/util/Util.as
@@ -52,7 +52,7 @@ public class Util
 
         if (defaults != null) {
             for (prop in defaults) {
-                if (!(prop in initProps)) {
+                if (initProps == null || !(prop in initProps)) {
                     target[prop] = defaults[prop];
                 }
             }