diff --git a/lambda/.gitignore b/lambda/.gitignore
index c4c4ffc..539f15b 100644
--- a/lambda/.gitignore
+++ b/lambda/.gitignore
@@ -1 +1,2 @@
 *.zip
+tmp/*
diff --git a/lambda/README.md b/lambda/README.md
index 7838a98..f2991bd 100644
--- a/lambda/README.md
+++ b/lambda/README.md
@@ -8,6 +8,7 @@
 2. Create a ZIP archive with the `tippecanoe` binary at `bin/tippecanoe` and upload as a Lambda layer
 3. Copy [lambda_function.py](lambda_function.py) (python 3.9 runtime)
 4. set the environment variable `OUTPUT_BUCKET` to your output bucket; give lambda IAM role access to input/output buckets
+5. Enable ACLs on the output bucket
 
 ```json
 {
@@ -17,13 +18,16 @@
             "Sid": "AllowGet",
             "Effect": "Allow",
             "Action": "s3:GetObject",
-            "Resource": "arn:aws:s3:::tippecanoe-lambda-input/*"
+            "Resource": "arn:aws:s3:::protomaps-tippecanoe-test/*"
         },
         {
             "Sid": "AllowPut",
             "Effect": "Allow",
-            "Action": "s3:PutObject",
-            "Resource": "arn:aws:s3:::tippecanoe-lambda-output/*"
+            "Action": [
+                "s3:PutObject",
+                "s3:PutObjectAcl"
+            ],
+            "Resource": "arn:aws:s3:::protomaps-tippecanoe-test-output/*"
         }
     ]
 }
diff --git a/lambda/tippecanoe.py b/lambda/tippecanoe.py
index 4fd3867..b76e8e5 100644
--- a/lambda/tippecanoe.py
+++ b/lambda/tippecanoe.py
@@ -3,9 +3,10 @@ import json
 import subprocess
 import sys
 import boto3
+from botocore import UNSIGNED
+from botocore.config import Config
+
 # if the input bucket is publicly readable
-# from botocore import UNSIGNED
-# from botocore.config import Config
 #s3 = boto3.client('s3',config=Config(signature_version=UNSIGNED))
 
 def lambda_handler(event, context):
@@ -36,7 +37,7 @@ def run_tippecanoe(executable, tmpdir, bucket_name, input_key):
     for line in p.stderr:
         try:
             j = json.loads(line)
-            s3.put_object(Body=json.dumps(j),Bucket=os.environ['OUTPUT_BUCKET'],Key=root + ".progress")
+            s3.put_object(Body=json.dumps(j),Bucket=os.environ['OUTPUT_BUCKET'],Key=root + ".progress",ACL="public-read",ContentType="application/json",ContentDisposition="inline")
         except json.decoder.JSONDecodeError:
             pass
     s3.upload_file(output_path,os.environ['OUTPUT_BUCKET'],root + ".mbtiles")