diff --git a/explorer/actions.py b/explorer/actions.py
index 5b90a289..7972b9b0 100644
--- a/explorer/actions.py
+++ b/explorer/actions.py
@@ -21,7 +21,7 @@ def generate_report(modeladmin, request, queryset):
             content_type=queries["content_type"]
         )
         response["Content-Disposition"] = queries["filename"]
-        response["Content-Length"] = queries["length"]
+        response["Content-Length"] = len(response.content)
         return response
 
     generate_report.short_description = description
@@ -43,7 +43,6 @@ def _package(queries):
         is_one and CSVExporter(queries[0]).get_output()
     ) or _build_zip(queries)
 
-    ret["length"] = (is_one and len(ret["data"]) or ret["data"].blksize)
     return ret
 
 
diff --git a/explorer/tests/test_actions.py b/explorer/tests/test_actions.py
index c4018d30..cc24d112 100644
--- a/explorer/tests/test_actions.py
+++ b/explorer/tests/test_actions.py
@@ -1,4 +1,5 @@
 import io
+from unittest.mock import patch
 from zipfile import ZipFile
 
 from django.test import TestCase
@@ -16,6 +17,16 @@ def test_single_query_is_csv_file(self):
         fn = generate_report_action()
         result = fn(None, None, [r, ])
         self.assertEqual(result.content.lower().decode("utf-8-sig"), expected_csv)
+        self.assertEqual(int(result["Content-Length"]), len(result.content))
+
+    @patch("explorer.actions.CSVExporter.get_output")
+    def test_single_query_with_unicode_has_byte_content_length(self, get_output):
+        get_output.return_value = "name\r\nЗавершен\r\n"
+
+        result = generate_report_action()(None, None, [SimpleQueryFactory()])
+
+        self.assertEqual(int(result["Content-Length"]), len(result.content))
+        self.assertGreater(len(result.content), len(get_output.return_value))
 
     def test_multiple_queries_are_zip_file(self):
 
@@ -32,6 +43,7 @@ def test_multiple_queries_are_zip_file(self):
         self.assertEqual(len(z.namelist()), 2)
         self.assertEqual(z.namelist()[0], f"{q.title}.csv")
         self.assertEqual(got_csv.lower().decode("utf-8-sig"), expected_csv)
+        self.assertEqual(int(res["Content-Length"]), len(res.content))
 
     # if commas are not removed from the filename, then Chrome throws
     # "duplicate headers received from server"