diff --git a/app/services/s3_storage.py b/app/services/s3_storage.py
index 4f105f1..09ee39a 100644
--- a/app/services/s3_storage.py
+++ b/app/services/s3_storage.py
@@ -77,7 +77,7 @@ class S3Storage:
         self.ensure_bucket()
         url = self.client.generate_presigned_url(
             "put_object",
-            Params={"Bucket": self.bucket, "Key": key},
+            Params={"Bucket": self.bucket, "Key": key, "ContentType": mime_type},
             ExpiresIn=expires_sec,
             HttpMethod="PUT",
         )
diff --git a/tests/test_uploads_s3.py b/tests/test_uploads_s3.py
index 0ea72f3..85d7512 100644
--- a/tests/test_uploads_s3.py
+++ b/tests/test_uploads_s3.py
@@ -979,5 +979,11 @@ class UploadsS3Tests(unittest.TestCase):
         self.assertTrue(second.startswith("/s3/"))
         self.assertEqual(fake_client.head_bucket_calls, 1)
         self.assertEqual(fake_client.create_bucket_calls, 0)
-        self.assertEqual(fake_client.presign_params[0], {"Bucket": settings.S3_BUCKET, "Key": "avatars/test-user/photo.png"})
-        self.assertEqual(fake_client.presign_params[1], {"Bucket": settings.S3_BUCKET, "Key": "avatars/test-user/photo-2.png"})
+        self.assertEqual(
+            fake_client.presign_params[0],
+            {"Bucket": settings.S3_BUCKET, "Key": "avatars/test-user/photo.png", "ContentType": "image/png"},
+        )
+        self.assertEqual(
+            fake_client.presign_params[1],
+            {"Bucket": settings.S3_BUCKET, "Key": "avatars/test-user/photo-2.png", "ContentType": "image/png"},
+        )