diff --git a/exodus_lambda/functions/origin_request.py b/exodus_lambda/functions/origin_request.py
index 28f8c255..daa75801 100755
--- a/exodus_lambda/functions/origin_request.py
+++ b/exodus_lambda/functions/origin_request.py
@@ -1,5 +1,6 @@
 import binascii
 import functools
+import gzip
 import json
 import os
 import time
@@ -65,7 +66,15 @@ def definitions(self):
             )
             if query_result["Items"]:
                 item = query_result["Items"][0]
-                out = json.loads(item["config"]["S"])
+                if item_encoded := item["config"].get("B"):
+                    # new-style: config is compressed and stored as bytes
+                    item_bytes = b64decode(item_encoded)
+                    item_json = gzip.decompress(item_bytes).decode()
+                else:
+                    # old-style, config was stored as JSON string.
+                    # Consider deleting this code path in 2025
+                    item_json = item["config"]["S"]
+                out = json.loads(item_json)
             else:
                 # Provide dict with expected keys when no config is found.
                 out = {
diff --git a/tests/functions/test_origin_request.py b/tests/functions/test_origin_request.py
index 0f2de2ee..02ad523e 100644
--- a/tests/functions/test_origin_request.py
+++ b/tests/functions/test_origin_request.py
@@ -1,5 +1,7 @@
+import gzip
 import json
 import logging
+from base64 import b64encode
 from urllib.parse import unquote, urlencode
 
 import mock
@@ -342,15 +344,25 @@ def test_origin_request_invalid_item(
     )
 
 
+@pytest.mark.parametrize("binary_config", (True, False))
 @mock.patch("boto3.client")
-def test_origin_request_definitions(mocked_boto3_client):
+def test_origin_request_definitions(mocked_boto3_client, binary_config: bool):
     mocked_defs = mock_definitions()
+    json_defs = json.dumps(mocked_defs)
+
+    if binary_config:
+        # Config in the style exodus-gw writes from late 2024 onwards
+        config = {"B": b64encode(gzip.compress(json_defs.encode())).decode()}
+    else:
+        # Older-style config
+        config = {"S": json_defs}
+
     mocked_boto3_client().query.return_value = {
         "Items": [
             {
                 "from_date": {"S": "2020-02-17T00:00:00.000+00:00"},
                 "config_id": {"S": "exodus-config"},
-                "config": {"S": json.dumps(mocked_defs)},
+                "config": config,
             }
         ]
     }