diff --git a/src/main/kotlin/ru/dbotthepony/kstarbound/Starbound.kt b/src/main/kotlin/ru/dbotthepony/kstarbound/Starbound.kt
index 8b398363..562fc294 100644
--- a/src/main/kotlin/ru/dbotthepony/kstarbound/Starbound.kt
+++ b/src/main/kotlin/ru/dbotthepony/kstarbound/Starbound.kt
@@ -389,7 +389,9 @@ class Starbound : ISBFileLocator {
 					t: Object2ObjectOpenHashMap<String, ArrayList<IStarboundFile>>,
 					u: Object2ObjectOpenHashMap<String, ArrayList<IStarboundFile>>
 				): Object2ObjectOpenHashMap<String, ArrayList<IStarboundFile>> {
-					t.putAll(u)
+					for ((k, v) in u)
+						t.computeIfAbsent(k, Object2ObjectFunction { ArrayList() }).addAll(v)
+
 					return t
 				}