diff --git a/crates/opensi-core/src/lib.rs b/crates/opensi-core/src/lib.rs
index ee1fe2d..e35660c 100644
--- a/crates/opensi-core/src/lib.rs
+++ b/crates/opensi-core/src/lib.rs
@@ -516,7 +516,7 @@ impl Package {
         }
     }
 
-    pub fn to_bytes(self) -> Result<Vec<u8>, Error> {
+    pub fn to_bytes(&self) -> Result<Vec<u8>, Error> {
         let buffer = Vec::new();
         let cursor = io::Cursor::new(buffer);
         let mut zip = ZipWriter::new(cursor);
@@ -531,7 +531,8 @@ impl Package {
         zip.start_file("[Content_Types].xml", options)?;
         zip.write_all(Self::CONTENT_TYPE_FILE_CONTENT.as_ref())?;
 
-        for (key, value) in self.resource.into_iter() {
+        let resources = &self.resource;
+        for (key, value) in resources.into_iter() {
             zip.start_file(key.extract_key(), options)?;
             zip.write_all(&value)?
         }
diff --git a/crates/opensi-core/tests/test.rs b/crates/opensi-core/tests/test.rs
index ade0220..94afa34 100644
--- a/crates/opensi-core/tests/test.rs
+++ b/crates/opensi-core/tests/test.rs
@@ -16,3 +16,13 @@ fn read_package_name() {
     let package = Package::open_zip_file(PATH).expect("pack is not found");
     assert_eq!(package.name, "SLAM JAM 2".to_owned());
 }
+
+#[test]
+fn resave_test() {
+    let package_original = Package::open_zip_file(PATH).expect("Pack is not found");
+    let bytes = &package_original.to_bytes().expect("Can't serialize package to bytes");
+    let package_resaved = Package::from_zip_buffer(bytes)
+        .expect("Can't read package from buffer");
+
+    assert_eq!(package_original, package_resaved);
+}
\ No newline at end of file