diff --git a/rhodecode/apps/repository/views/repo_files.py b/rhodecode/apps/repository/views/repo_files.py
--- a/rhodecode/apps/repository/views/repo_files.py
+++ b/rhodecode/apps/repository/views/repo_files.py
@@ -808,9 +808,11 @@ class RepoFilesView(RepoAppView):
         safe_path = f_name.replace('"', '\\"')
         encoded_path = urllib.parse.quote(f_name)
 
-        return "attachment; " \
-               "filename=\"{}\"; " \
-               "filename*=UTF-8\'\'{}".format(safe_path, encoded_path)
+        headers = "attachment; " \
+                  "filename=\"{}\"; " \
+                  "filename*=UTF-8\'\'{}".format(safe_path, encoded_path)
+
+        return headers.encode().decode('iso-8859-1', errors='replace')
 
     @LoginRequired()
     @HasRepoPermissionAnyDecorator(