diff --git a/services/docstore/config/settings.defaults.js b/services/docstore/config/settings.defaults.js
index d22ff8fee1..0483ecbc3e 100644
--- a/services/docstore/config/settings.defaults.js
+++ b/services/docstore/config/settings.defaults.js
@@ -17,8 +17,15 @@ const Settings = {
   mongo: {},
 
   docstore: {
+    backend: process.env.BACKEND || 's3',
     healthCheck: {
       project_id: process.env.HEALTH_CHECK_PROJECT_ID
+    },
+    bucket: process.env.BUCKET_NAME || 'bucket',
+    gcs: {
+      unlockBeforeDelete: process.env.GCS_UNLOCK_BEFORE_DELETE === 'true',
+      deletedBucketSuffix: process.env.GCS_DELETED_BUCKET_SUFFIX,
+      deleteConcurrency: parseInt(process.env.GCS_DELETE_CONCURRENCY) || 50
     }
   },
 
@@ -41,7 +48,28 @@ if (
   Settings.docstore.s3 = {
     key: process.env.AWS_ACCESS_KEY_ID,
     secret: process.env.AWS_SECRET_ACCESS_KEY,
-    bucket: process.env.AWS_BUCKET
+    bucket: process.env.AWS_BUCKET,
+    endpoint: process.env.AWS_S3_ENDPOINT,
+    pathStyle: process.env.AWS_S3_PATH_STYLE,
+    partSize: parseInt(process.env.AWS_S3_PARTSIZE) || 100 * 1024 * 1024
+  }
+}
+
+if (process.env.GCS_API_ENDPOINT) {
+  Settings.docstore.gcs.endpoint = {
+    apiEndpoint: process.env.GCS_API_ENDPOINT,
+    apiScheme: process.env.GCS_API_SCHEME,
+    projectId: process.env.GCS_PROJECT_ID
+  }
+}
+
+if (process.env.FALLBACK_BACKEND) {
+  Settings.docstore.fallback = {
+    backend: process.env.FALLBACK_BACKEND,
+    // mapping of bucket names on the fallback, to bucket names on the primary.
+    // e.g. { myS3UserFilesBucketName: 'myGoogleUserFilesBucketName' }
+    buckets: JSON.parse(process.env.FALLBACK_BUCKET_MAPPING || '{}'),
+    copyOnMiss: process.env.COPY_ON_MISS === 'true'
   }
 }