diff --git a/parquet_tools/commands/csv.py b/parquet_tools/commands/csv.py
index eb46af4..d2e7cf0 100644
--- a/parquet_tools/commands/csv.py
+++ b/parquet_tools/commands/csv.py
@@ -1,3 +1,4 @@
+import os
 import sys
 from argparse import ArgumentParser, Namespace
 from typing import List, Optional
@@ -34,7 +35,7 @@ def configure_parser(paser: ArgumentParser) -> ArgumentParser:
     paser.add_argument('--endpoint-url',
                        type=str,
                        required=False,
-                       default=None,
+                       default=os.environ.get('ENDPOINT_URL'),
                        help='A custom S3 endpoint URL')
     paser.set_defaults(handler=_cli)
     return paser
diff --git a/parquet_tools/commands/inspect.py b/parquet_tools/commands/inspect.py
index 5b0da65..d776079 100644
--- a/parquet_tools/commands/inspect.py
+++ b/parquet_tools/commands/inspect.py
@@ -1,3 +1,4 @@
+import os
 import sys
 from argparse import ArgumentParser, Namespace
 from typing import List
@@ -33,6 +34,7 @@ def configure_parser(paser: ArgumentParser) -> ArgumentParser:
                        type=str,
                        required=False,
                        default=None,
+                       default=os.environ.get('ENDPOINT_URL'),
                        help='A custom S3 endpoint URL')
 
     paser.set_defaults(handler=_cli)
diff --git a/parquet_tools/commands/show.py b/parquet_tools/commands/show.py
index 9ab01a2..965ddb1 100644
--- a/parquet_tools/commands/show.py
+++ b/parquet_tools/commands/show.py
@@ -1,3 +1,4 @@
+import os
 import sys
 from argparse import ArgumentParser, Namespace
 from logging import getLogger
@@ -49,7 +50,7 @@ def configure_parser(paser: ArgumentParser) -> ArgumentParser:
     paser.add_argument('--endpoint-url',
                        type=str,
                        required=False,
-                       default=None,
+                       default=os.environ.get('ENDPOINT_URL'),
                        help='A custom S3 endpoint URL')
 
     paser.set_defaults(handler=_cli)