diff --git a/zerver/lib/upload/__init__.py b/zerver/lib/upload/__init__.py
index a7c701c0c7..1d5dcc1e4f 100644
--- a/zerver/lib/upload/__init__.py
+++ b/zerver/lib/upload/__init__.py
@@ -44,7 +44,7 @@ def create_attachment(
     file_name: str,
     path_id: str,
     content_type: str,
-    file_size: int,
+    file_data: bytes,
     user_profile: UserProfile,
     realm: Realm,
 ) -> None:
@@ -56,7 +56,7 @@ def create_attachment(
         path_id=path_id,
         owner=user_profile,
         realm=realm,
-        size=file_size,
+        size=len(file_data),
         content_type=content_type,
     )
     from zerver.actions.uploads import notify_attachment_update
@@ -144,7 +144,7 @@ def upload_message_attachment(
         uploaded_file_name,
         path_id,
         content_type,
-        len(file_data),
+        file_data,
         user_profile,
         target_realm,
     )
diff --git a/zerver/tests/test_message_fetch.py b/zerver/tests/test_message_fetch.py
index f29492cee1..f2c9967ad3 100644
--- a/zerver/tests/test_message_fetch.py
+++ b/zerver/tests/test_message_fetch.py
@@ -4517,17 +4517,16 @@ class MessageHasKeywordsTest(ZulipTestCase):
     """Test for keywords like has_link, has_image, has_attachment."""
 
     def setup_dummy_attachments(self, user_profile: UserProfile) -> List[str]:
-        sample_size = 10
         realm_id = user_profile.realm_id
         dummy_files = [
-            ("zulip.txt", f"{realm_id}/31/4CBjtTLYZhk66pZrF8hnYGwc/zulip.txt", sample_size),
-            ("temp_file.py", f"{realm_id}/31/4CBjtTLYZhk66pZrF8hnYGwc/temp_file.py", sample_size),
-            ("abc.py", f"{realm_id}/31/4CBjtTLYZhk66pZrF8hnYGwc/abc.py", sample_size),
+            ("zulip.txt", f"{realm_id}/31/4CBjtTLYZhk66pZrF8hnYGwc/zulip.txt"),
+            ("temp_file.py", f"{realm_id}/31/4CBjtTLYZhk66pZrF8hnYGwc/temp_file.py"),
+            ("abc.py", f"{realm_id}/31/4CBjtTLYZhk66pZrF8hnYGwc/abc.py"),
         ]
 
-        for file_name, path_id, size in dummy_files:
+        for file_name, path_id in dummy_files:
             create_attachment(
-                file_name, path_id, "text/plain", size, user_profile, user_profile.realm
+                file_name, path_id, "text/plain", b"1234567890", user_profile, user_profile.realm
             )
 
         # return path ids
diff --git a/zerver/tests/test_retention.py b/zerver/tests/test_retention.py
index b2b535b7f9..edbf8ae3c3 100644
--- a/zerver/tests/test_retention.py
+++ b/zerver/tests/test_retention.py
@@ -180,18 +180,17 @@ class ArchiveMessagesTestingBase(RetentionTestingBase):
 
     def _send_messages_with_attachments(self) -> Dict[str, int]:
         user_profile = self.example_user("hamlet")
-        sample_size = 10
         host = user_profile.realm.host
         realm_id = get_realm("zulip").id
         dummy_files = [
-            ("zulip.txt", f"{realm_id}/31/4CBjtTLYZhk66pZrF8hnYGwc/zulip.txt", sample_size),
-            ("temp_file.py", f"{realm_id}/31/4CBjtTLYZhk66pZrF8hnYGwc/temp_file.py", sample_size),
-            ("abc.py", f"{realm_id}/31/4CBjtTLYZhk66pZrF8hnYGwc/abc.py", sample_size),
+            ("zulip.txt", f"{realm_id}/31/4CBjtTLYZhk66pZrF8hnYGwc/zulip.txt"),
+            ("temp_file.py", f"{realm_id}/31/4CBjtTLYZhk66pZrF8hnYGwc/temp_file.py"),
+            ("abc.py", f"{realm_id}/31/4CBjtTLYZhk66pZrF8hnYGwc/abc.py"),
         ]
 
-        for file_name, path_id, size in dummy_files:
+        for file_name, path_id in dummy_files:
             create_attachment(
-                file_name, path_id, "text/plain", size, user_profile, user_profile.realm
+                file_name, path_id, "text/plain", b"1234567890", user_profile, user_profile.realm
             )
 
         self.subscribe(user_profile, "Denmark")
@@ -594,19 +593,18 @@ class MoveMessageToArchiveBase(RetentionTestingBase):
         self.recipient = self.example_user("cordelia")
 
     def _create_attachments(self) -> None:
-        sample_size = 10
         realm_id = get_realm("zulip").id
         dummy_files = [
-            ("zulip.txt", f"{realm_id}/31/4CBjtTLYZhk66pZrF8hnYGwc/zulip.txt", sample_size),
-            ("temp_file.py", f"{realm_id}/31/4CBjtTLYZhk66pZrF8hnYGwc/temp_file.py", sample_size),
-            ("abc.py", f"{realm_id}/31/4CBjtTLYZhk66pZrF8hnYGwc/abc.py", sample_size),
-            ("hello.txt", f"{realm_id}/31/4CBjtTLYZhk66pZrF8hnYGwc/hello.txt", sample_size),
-            ("new.py", f"{realm_id}/31/4CBjtTLYZhk66pZrF8hnYGwc/new.py", sample_size),
+            ("zulip.txt", f"{realm_id}/31/4CBjtTLYZhk66pZrF8hnYGwc/zulip.txt"),
+            ("temp_file.py", f"{realm_id}/31/4CBjtTLYZhk66pZrF8hnYGwc/temp_file.py"),
+            ("abc.py", f"{realm_id}/31/4CBjtTLYZhk66pZrF8hnYGwc/abc.py"),
+            ("hello.txt", f"{realm_id}/31/4CBjtTLYZhk66pZrF8hnYGwc/hello.txt"),
+            ("new.py", f"{realm_id}/31/4CBjtTLYZhk66pZrF8hnYGwc/new.py"),
         ]
         user_profile = self.example_user("hamlet")
-        for file_name, path_id, size in dummy_files:
+        for file_name, path_id in dummy_files:
             create_attachment(
-                file_name, path_id, "text/plain", size, user_profile, user_profile.realm
+                file_name, path_id, "text/plain", b"1234567890", user_profile, user_profile.realm
             )
 
     def _assert_archive_empty(self) -> None: