From 0841051602b7bc77afa6f7cf53d247a409d79cbc Mon Sep 17 00:00:00 2001
From: Hugo Dutka <hugo@coder.com>
Date: Tue, 24 Feb 2026 11:20:19 +0100
Subject: [PATCH] fix(slack): better file handling

---
 packages/slack/src/message.ts | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/packages/slack/src/message.ts b/packages/slack/src/message.ts
index 19d8d0e..cce864f 100644
--- a/packages/slack/src/message.ts
+++ b/packages/slack/src/message.ts
@@ -631,7 +631,14 @@ export const extractMessagesMetadata = async <
               const text = await response.text();
               throw new Error(text);
             }
-            if (response.headers.get("content-type") !== file.mimetype) {
+            const responseContentType = response.headers
+              .get("content-type")
+              ?.split(";")[0]
+              ?.trim();
+            if (
+              !responseContentType ||
+              !supportedFileTypes.includes(responseContentType)
+            ) {
               throw new Error(
                 `The file ${file.name} mime type returned by the server was ${response.headers.get("content-type")}.`
               );