diff --git a/mautrix_twitter/portal.py b/mautrix_twitter/portal.py
index 5d2e624..034d3a0 100644
--- a/mautrix_twitter/portal.py
+++ b/mautrix_twitter/portal.py
@@ -353,8 +353,7 @@ async def _handle_matrix_message(
             mime_type = message.info.mimetype or magic.from_buffer(data, mime=True)
             upload_resp = await sender.client.upload(data, mime_type=mime_type)
             media_id = upload_resp.media_id
-            filename = message.get("filename", None)
-            if filename and filename != message.body:
+            if message.filename and message.filename != message.body:
                 text = message.body
             else:
                 text = ""
@@ -511,11 +510,11 @@ async def _convert_twitter_message(
             if reply_to_msg:
                 text_content.set_reply(reply_to_msg.mxid)
             if media_content and self.config["bridge.caption_in_message"]:
-                media_content["filename"] = media_content.body
+                media_content.filename = media_content.body
                 media_content.body = text_content.body
                 if text_content.formatted_body:
-                    media_content["format"] = str(text_content.format)
-                    media_content["formatted_body"] = text_content.formatted_body
+                    media_content.format = text_content.format
+                    media_content.formatted_body = text_content.formatted_body
             else:
                 converted.append(text_content)
         return converted
diff --git a/requirements.txt b/requirements.txt
index f8c9439..fc30f1f 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -4,5 +4,5 @@ commonmark>=0.8,<0.10
 aiohttp>=3,<4
 yarl>=1,<2
 attrs>=20.1
-mautrix>=0.20.2,<0.21
+mautrix>=0.20.5,<0.21
 asyncpg>=0.20,<0.29
diff --git a/setup.py b/setup.py
index 2b131e9..b3b3bd8 100644
--- a/setup.py
+++ b/setup.py
@@ -48,7 +48,7 @@
 
     install_requires=install_requires,
     extras_require=extras_require,
-    python_requires="~=3.8",
+    python_requires="~=3.9",
 
     classifiers=[
         "Development Status :: 4 - Beta",
@@ -57,7 +57,6 @@
         "Framework :: AsyncIO",
         "Programming Language :: Python",
         "Programming Language :: Python :: 3",
-        "Programming Language :: Python :: 3.8",
         "Programming Language :: Python :: 3.9",
         "Programming Language :: Python :: 3.10",
     ],