diff --git a/source/cdcdb/snapshot.d b/source/cdcdb/snapshot.d
index 8cd534e..2b72309 100644
--- a/source/cdcdb/snapshot.d
+++ b/source/cdcdb/snapshot.d
@@ -38,7 +38,7 @@ private:
 public:
 	this(DBLite dblite, DBSnapshot dbSnapshot) { _db = dblite; _snapshot = dbSnapshot; }
 
-	ubyte[] data()
+	immutable(ubyte[]) data()
 	{
 		auto chunks = _db.getChunks(_snapshot.id);
 		ubyte[] content;
@@ -55,7 +55,7 @@ public:
 
 		enforce(_snapshot.sha256 == fctx.finish(), "Хеш итогового файла не совпадает");
 
-		return content;
+		return content.idup;
 	}
 
 	void data(void delegate(const(ubyte)[]) sink)