diff --git a/src/lime/utils/AssetLibrary.hx b/src/lime/utils/AssetLibrary.hx
index 9f25ab973..a010d55d3 100644
--- a/src/lime/utils/AssetLibrary.hx
+++ b/src/lime/utils/AssetLibrary.hx
@@ -769,6 +769,7 @@ class AssetLibrary {
 		for (asset in manifest.assets) {
 
 			size = hasSize ? asset.size : 100;
+			if (size == null) size = 100;
 			id = asset.id;
 
 			if (Reflect.hasField (asset, "path")) {