diff --git a/README.md b/README.md
index fed2b5a4..6fc1cbb7 100644
--- a/README.md
+++ b/README.md
@@ -9,6 +9,8 @@
   - [Architecture](#architecture)
   - [Migration](#migration)
     - [Warnings](#warnings)
+    - [4.1.0](#410)
+      - [Thumbnails feature disabled by default](#thumbnails-feature-disabled-by-default)
     - [4.0.0](#400)
       - [Context Extension disabled by default](#context-extension-disabled-by-default)
       - [Node 22 update](#node-22-update)
@@ -170,6 +172,13 @@ apiLambda --> opensearch
   name, reindex the existing index into the newly-created index, delete and re-created
   the existing index by creating a collection, and reindex back into the index.
 
+### 4.1.0
+
+#### Thumbnails feature disabled by default
+
+The thumbnails behavior is now disabled by default, and can be enabled with
+`ENABLE_THUMBNAILS` = `true`.
+
 ### 4.0.0
 
 #### Context Extension disabled by default
@@ -417,7 +426,8 @@ Properties: . . .
 #### Granting Access for Thumbnails
 
 The new experimental endpoint `/collections/{c_id}/items/{item_id}/thumbnail` will
-redirect to a URL providing a thumbnail as determined by the assets in an item. If the
+redirect to a URL providing a thumbnail as determined by the assets in an item. This is
+enabled only if `ENABLE_THUMBNAILS` is set to `true`. If the
 href for this is an AWS S3 ARN, IAM permissions must be granted for the API Lambda to
 generate a pre-signed HTTP URL instead. For example:
 
@@ -599,6 +609,7 @@ There are some settings that should be reviewed and updated as needeed in the se
 | CORS_METHODS                     | Configure whether or not to send the `Access-Control-Allow-Methods` CORS header. Expects a comma-delimited string, e.g., `GET,PUT,POST`.                                                                                                                                        | `GET,HEAD,PUT,PATCH,POST,DELETE`                                                     |
 | CORS_HEADERS                     | Configure whether or not to send the `Access-Control-Allow-Headers` CORS header. Expects a comma-delimited string, e.g., `Content-Type,Authorization`. If not specified, defaults to reflecting the headers specified in the request’s `Access-Control-Request-Headers` header. | none                                                                                 |
 | ENABLE_COLLECTIONS_AUTHX         | Enables support for hidden `_collections` query parameter / field when set to `true`.                                                                                                                                                                                                              | none                                                                                 |
+| ENABLE_THUMBNAILS         | Enables support for presigned thumnails.                                                                                                                                                                                                              | none                                                                                 |
 
 Additionally, the credential for OpenSearch must be configured, as decribed in the
 section [Populating and accessing credentials](#populating-and-accessing-credentials).
diff --git a/src/lib/api.js b/src/lib/api.js
index 4f9fbf9c..c018e33a 100644
--- a/src/lib/api.js
+++ b/src/lib/api.js
@@ -484,10 +484,12 @@ export const addItemLinks = function (results, endpoint) {
       type: 'application/json',
       href: `${endpoint}`
     })
-    links.push({
-      rel: 'thumbnail',
-      href: `${endpoint}/collections/${collection}/items/${id}/thumbnail`
-    })
+    if (process.env['ENABLE_THUMBNAILS'] === 'true') {
+      links.push({
+        rel: 'thumbnail',
+        href: `${endpoint}/collections/${collection}/items/${id}/thumbnail`
+      })
+    }
     result.type = 'Feature'
     return result
   })
@@ -1312,6 +1314,10 @@ const deleteItem = async function (collectionId, itemId, backend) {
 }
 
 const getItemThumbnail = async function (collectionId, itemId, backend, queryParameters) {
+  if (process.env['ENABLE_THUMBNAILS'] !== 'true') {
+    return new NotFoundError()
+  }
+
   if (!isCollectionIdAllowed(extractAllowedCollectionIds(queryParameters), collectionId)) {
     return new NotFoundError()
   }
diff --git a/tests/system/test-api-item-get.js b/tests/system/test-api-item-get.js
index 64144856..17cac0f4 100644
--- a/tests/system/test-api-item-get.js
+++ b/tests/system/test-api-item-get.js
@@ -122,6 +122,7 @@ test('GET /collections/:collectionId/items/:itemId with restriction returns filt
 
 test('GET /collections/:collectionId/items/:itemId/thumbnail with restriction returns filtered collections', async (t) => {
   process.env['ENABLE_COLLECTIONS_AUTHX'] = 'true'
+  process.env['ENABLE_THUMBNAILS'] = 'true'
 
   const { collectionId, itemId } = t.context
 
@@ -159,3 +160,14 @@ test('GET /collections/:collectionId/items/:itemId/thumbnail with restriction re
       searchParams: { _collections: 'not-a-collection' }
     })).statusCode, 404)
 })
+
+test('GET /collections/:collectionId/items/:itemId/thumbnail disabled', async (t) => {
+  process.env['ENABLE_THUMBNAILS'] = 'false'
+
+  const { collectionId, itemId } = t.context
+
+  const path = `collections/${collectionId}/items/${itemId}/thumbnail`
+
+  t.is((await t.context.api.client.get(path,
+    { resolveBodyOnly: false, throwHttpErrors: false })).statusCode, 404)
+})