diff --git a/slack_sdk/audit_logs/v1/async_client.py b/slack_sdk/audit_logs/v1/async_client.py
index 24e22ec6..af901109 100644
--- a/slack_sdk/audit_logs/v1/async_client.py
+++ b/slack_sdk/audit_logs/v1/async_client.py
@@ -279,7 +279,7 @@ async def _perform_http_request(
                     )
 
                 try:
-                    async with session.request(http_verb, url, **request_kwargs) as res:  # type: ignore[arg-type, union-attr] # noqa: E501
+                    async with session.request(http_verb, url, **request_kwargs) as res:  # type: ignore[union-attr] # noqa: E501
                         try:
                             response_body = await res.text()
                             retry_response = RetryHttpResponse(
diff --git a/slack_sdk/web/async_client.py b/slack_sdk/web/async_client.py
index 822b75f6..b7ea4077 100644
--- a/slack_sdk/web/async_client.py
+++ b/slack_sdk/web/async_client.py
@@ -3757,7 +3757,7 @@ async def files_upload_v2(
         # To upload multiple files at a time
         file_uploads: Optional[List[Dict[str, Any]]] = None,
         channel: Optional[str] = None,
-        channels: Optional[Sequence[str]] = None,
+        channels: Optional[List[str]] = None,
         initial_comment: Optional[str] = None,
         thread_ts: Optional[str] = None,
         request_file_info: bool = True,  # since v3.23, this flag is no longer necessary
diff --git a/slack_sdk/web/client.py b/slack_sdk/web/client.py
index d4129430..55e9763d 100644
--- a/slack_sdk/web/client.py
+++ b/slack_sdk/web/client.py
@@ -3747,7 +3747,7 @@ def files_upload_v2(
         # To upload multiple files at a time
         file_uploads: Optional[List[Dict[str, Any]]] = None,
         channel: Optional[str] = None,
-        channels: Optional[Sequence[str]] = None,
+        channels: Optional[List[str]] = None,
         initial_comment: Optional[str] = None,
         thread_ts: Optional[str] = None,
         request_file_info: bool = True,  # since v3.23, this flag is no longer necessary
diff --git a/slack_sdk/web/legacy_client.py b/slack_sdk/web/legacy_client.py
index 9c8d272b..18f74563 100644
--- a/slack_sdk/web/legacy_client.py
+++ b/slack_sdk/web/legacy_client.py
@@ -3759,7 +3759,7 @@ def files_upload_v2(
         # To upload multiple files at a time
         file_uploads: Optional[List[Dict[str, Any]]] = None,
         channel: Optional[str] = None,
-        channels: Optional[Sequence[str]] = None,
+        channels: Optional[List[str]] = None,
         initial_comment: Optional[str] = None,
         thread_ts: Optional[str] = None,
         request_file_info: bool = True,  # since v3.23, this flag is no longer necessary
diff --git a/slack_sdk/webhook/async_client.py b/slack_sdk/webhook/async_client.py
index a737b4e3..f3decf89 100644
--- a/slack_sdk/webhook/async_client.py
+++ b/slack_sdk/webhook/async_client.py
@@ -192,7 +192,7 @@ async def _perform_http_request(self, *, body: Dict[str, Any], headers: Dict[str
                     self.logger.debug(f"Sending a request - url: {self.url}, body: {str_body}, headers: {headers}")
 
                 try:
-                    async with session.request("POST", self.url, **request_kwargs) as res:  # type: ignore[arg-type, union-attr] # noqa: E501
+                    async with session.request("POST", self.url, **request_kwargs) as res:  # type: ignore[union-attr] # noqa: E501
                         try:
                             response_body = await res.text()
                             retry_response = RetryHttpResponse(