diff --git a/package/cloudshell/cm/customscript/domain/script_downloader.py b/package/cloudshell/cm/customscript/domain/script_downloader.py
index a9773e5..753132f 100644
--- a/package/cloudshell/cm/customscript/domain/script_downloader.py
+++ b/package/cloudshell/cm/customscript/domain/script_downloader.py
@@ -77,7 +77,7 @@ def download(self, url, auth):
 
         for chunk in response.iter_content(ScriptDownloader.CHUNK_SIZE):
             if chunk:
-                file_txt += ''.join(chunk)
+                file_txt += ''.join(str(chunk))
             self.cancel_sampler.throw_if_canceled()
 
         self._validate_file(file_txt)