diff --git a/google/cloud/storage/blob.py b/google/cloud/storage/blob.py
index 31aeb05ef..d61081c44 100644
--- a/google/cloud/storage/blob.py
+++ b/google/cloud/storage/blob.py
@@ -818,8 +818,8 @@ def _extract_headers_from_download(self, response):
                 method, digest = match.groups()
                 digests[method] = digest
 
-        self.crc32c = digests.get("crc32c", None)
-        self.md5_hash = digests.get("md5", None)
+        self.crc32c = digests.get("crc32c", self.crc32c)
+        self.md5_hash = digests.get("md5", self.md5_hash)
 
     def _do_download(
         self,
diff --git a/tests/unit/test_blob.py b/tests/unit/test_blob.py
index 9bf60d42d..c4fd7fb8b 100644
--- a/tests/unit/test_blob.py
+++ b/tests/unit/test_blob.py
@@ -1524,10 +1524,16 @@ def test_download_as_string_w_response_headers(self):
 
     def test_download_as_string_w_hash_response_header_none(self):
         blob_name = "blob-name"
+        md5_hash = "CS9tHYTtyFntzj7B9nkkJQ=="
+        crc32c = "4gcgLQ=="
         client = mock.Mock(spec=["_http"])
         bucket = _Bucket(client)
         media_link = "http://example.com/media/"
-        properties = {"mediaLink": media_link}
+        properties = {
+            "mediaLink": media_link,
+            "md5Hash": md5_hash,
+            "crc32c": crc32c,
+        }
         blob = self._make_one(blob_name, bucket=bucket, properties=properties)
 
         response = self._mock_requests_response(
@@ -1538,8 +1544,8 @@ def test_download_as_string_w_hash_response_header_none(self):
         )
         blob._extract_headers_from_download(response)
 
-        self.assertIsNone(blob.md5_hash)
-        self.assertIsNone(blob.crc32c)
+        self.assertEqual(blob.md5_hash, md5_hash)
+        self.assertEqual(blob.crc32c, crc32c)
 
     def test_download_as_bytes_w_generation_match(self):
         GENERATION_NUMBER = 6