diff --git a/src/shared/python/slack.py b/src/shared/python/slack.py
index a712933..29215df 100644
--- a/src/shared/python/slack.py
+++ b/src/shared/python/slack.py
@@ -4,10 +4,23 @@ import json
 import os
 from urllib import request, error
 
+_webhook_url = None
+
+
+def _get_webhook_url():
+    global _webhook_url
+    if _webhook_url is None:
+        import boto3
+        client = boto3.client("secretsmanager")
+        secret_arn = os.environ["SLACK_WEBHOOK_SECRET_ARN"]
+        response = client.get_secret_value(SecretId=secret_arn)
+        _webhook_url = response["SecretString"]
+    return _webhook_url
+
 
 def post_message(blocks, text="Afi Backup Monitor"):
     """Post a Block Kit message to Slack via webhook."""
-    webhook_url = os.environ["SLACK_WEBHOOK_URL"]
+    webhook_url = _get_webhook_url()
     payload = json.dumps({"text": text, "blocks": blocks}).encode()
 
     req = request.Request(
diff --git a/template.yaml b/template.yaml
index 5a7c0d6..fc4a9fa 100644
--- a/template.yaml
+++ b/template.yaml
@@ -12,10 +12,9 @@ Parameters:
   AfiPolicyId:
     Type: String
     Description: Afi backup policy ID to assign to new users
-  SlackWebhookUrl:
+  SlackWebhookSecretArn:
     Type: String
-    Description: Slack incoming webhook URL
-    NoEcho: true
+    Description: ARN of the Secrets Manager secret containing the Slack webhook URL
   AutoProtectSchedule:
     Type: String
     Default: 'cron(0 14 ? * MON *)'
@@ -36,7 +35,7 @@ Globals:
       Variables:
         AFI_API_KEY_SECRET_ARN: !Ref AfiApiKeySecretArn
         AFI_TENANT_ID: !Ref AfiTenantId
-        SLACK_WEBHOOK_URL: !Ref SlackWebhookUrl
+        SLACK_WEBHOOK_SECRET_ARN: !Ref SlackWebhookSecretArn
 
 Resources:
   SharedLayer:
@@ -67,7 +66,9 @@ Resources:
             - Effect: Allow
               Action:
                 - secretsmanager:GetSecretValue
-              Resource: !Ref AfiApiKeySecretArn
+              Resource:
+                - !Ref AfiApiKeySecretArn
+                - !Ref SlackWebhookSecretArn
       Events:
         WeeklySchedule:
           Type: Schedule
@@ -90,7 +91,9 @@ Resources:
             - Effect: Allow
               Action:
                 - secretsmanager:GetSecretValue
-              Resource: !Ref AfiApiKeySecretArn
+              Resource:
+                - !Ref AfiApiKeySecretArn
+                - !Ref SlackWebhookSecretArn
       Events:
         WeeklySchedule:
           Type: Schedule