diff --git a/pyslackersweb/contexts.py b/pyslackersweb/contexts.py
index 6bfd6539..79585b46 100644
--- a/pyslackersweb/contexts.py
+++ b/pyslackersweb/contexts.py
@@ -2,6 +2,7 @@
 
 from aiohttp import ClientSession, web
 from apscheduler.schedulers.asyncio import AsyncIOScheduler
+from slack.io.aiohttp import SlackAPI
 
 from . import tasks
 
@@ -33,4 +34,5 @@ async def background_jobs(app: web.Application) -> None:
 async def client_session(app: web.Application) -> None:
     async with ClientSession(raise_for_status=True) as session:
         app["client_session"] = session
+        app["slack_client"] = SlackAPI(token=app["slack_token"], session=session)
         yield
diff --git a/pyslackersweb/tasks.py b/pyslackersweb/tasks.py
index fddd4255..d3f88552 100644
--- a/pyslackersweb/tasks.py
+++ b/pyslackersweb/tasks.py
@@ -3,6 +3,8 @@
 from collections import Counter
 from typing import List
 
+import slack
+
 from aiohttp import web
 
 from .util.log import ContextAwareLoggerAdapter
@@ -69,7 +71,7 @@ async def _sync_github() -> None:
 
 
 def sync_slack_users(app: web.Application):
-    session = app["client_session"]
+    client = app["slack_client"]
 
     async def _sync_slack_users():
         logger.debug("Refreshing slack users cache.")
@@ -81,30 +83,11 @@ async def _sync_slack_users():
 
         try:
             counter = Counter()
-            while True:
-                params = {}
-                async with session.get(
-                    "https://slack.com/api/users.list",
-                    headers={"Authorization": f"Bearer {oauth_token}"},
-                    params=params,
-                ) as r:
-                    result = await r.json()
-
-                if not result["ok"]:
-                    logger.error("Error fetching users from slack", extra=result)
-                    return
-
-                for user in result["members"]:
-                    if user["deleted"] or user["is_bot"] or not user["tz"]:
-                        continue
-
-                    counter[user["tz"]] += 1
-
-                # next_cursor can be an empty string. We need to check if the value is truthy
-                if result.get("response_metadata", {}).get("next_cursor"):
-                    params["cursor"] = result["response_metadata"]["next_cursor"]
-                else:
-                    break
+            async for user in client.iter(slack.methods.USERS_LIST):
+                if user["deleted"] or user["is_bot"] or not user["tz"]:
+                    continue
+
+                counter[user["tz"]] += 1
 
             logger.debug(
                 "Found %s users across %s timezones",
@@ -124,7 +107,7 @@ async def _sync_slack_users():
 
 
 def sync_slack_channels(app: web.Application):
-    session = app["client_session"]
+    client = app["slack_client"]
 
     async def _sync_slack_channel():
         logger.debug("Refreshing slack channels cache.")
@@ -136,35 +119,16 @@ async def _sync_slack_channel():
 
         try:
             channels = []
-            while True:
-                params = {}
-                async with session.get(
-                    "https://slack.com/api/channels.list",
-                    headers={"Authorization": f"Bearer {oauth_token}"},
-                    params=params,
-                ) as r:
-                    result = await r.json()
-
-                    if not result["ok"]:
-                        logger.error("Error fetching channels from slack", extra=result)
-                        return
-
-                    for channel in result["channels"]:
-                        channels.append(
-                            Channel(
-                                id=channel["id"],
-                                name=channel["name"],
-                                topic=channel["topic"]["value"],
-                                purpose=channel["purpose"]["value"],
-                                members=channel["num_members"],
-                            )
-                        )
-
-                # next_cursor can be an empty string. We need to check if the value is truthy
-                if result.get("response_metadata", {}).get("next_cursor"):
-                    params["cursor"] = result["response_metadata"]["next_cursor"]
-                else:
-                    break
+            async for channel in client.iter(slack.methods.CHANNELS_LIST):
+                channels.append(
+                    Channel(
+                        id=channel["id"],
+                        name=channel["name"],
+                        topic=channel["topic"]["value"],
+                        purpose=channel["purpose"]["value"],
+                        members=channel["num_members"],
+                    )
+                )
 
             logger.debug("Found %s slack channels", len(channels))
 
diff --git a/requirements/base.txt b/requirements/base.txt
index dbc2a55b..c042ee1c 100644
--- a/requirements/base.txt
+++ b/requirements/base.txt
@@ -7,3 +7,4 @@ apscheduler==3.6.0
 gunicorn==19.9.0
 marshmallow==3.0.0rc7
 sentry-sdk==0.9.0
+slack-sansio==1.0.0