diff --git a/package-lock.json b/package-lock.json
index 10e1d74..5720b97 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1162,9 +1162,9 @@
       "dev": true
     },
     "@netlify/open-api": {
-      "version": "0.16.1",
-      "resolved": "https://registry.npmjs.org/@netlify/open-api/-/open-api-0.16.1.tgz",
-      "integrity": "sha512-lIU1on/4xF+Gz2bpnLry/3E6Ns3ICGgCP62n3LmL3eSKo94wCqiO/9nyq5NILawYVSRUZeIvEVi5DgnVyLWyww=="
+      "version": "0.18.0",
+      "resolved": "https://registry.npmjs.org/@netlify/open-api/-/open-api-0.18.0.tgz",
+      "integrity": "sha512-2pgw9SngxtxNcg0g4OJzhHRWmXE/sGpjBn0KfeyKH6kyrY4a3XcKwIZLKuxVLuHxgkpdoBbsFlJBTlsj61g8Dw=="
     },
     "@netlify/zip-it-and-ship-it": {
       "version": "1.3.12",
diff --git a/package.json b/package.json
index e96ccc1..53d7bec 100644
--- a/package.json
+++ b/package.json
@@ -54,7 +54,7 @@
     "node client"
   ],
   "dependencies": {
-    "@netlify/open-api": "^0.16.0",
+    "@netlify/open-api": "^0.18.0",
     "@netlify/zip-it-and-ship-it": "^1.3.12",
     "backoff": "^2.5.0",
     "clean-deep": "^3.3.0",
diff --git a/src/operations.test.js.md b/src/operations.test.js.md
index e08a513..35e3289 100644
--- a/src/operations.test.js.md
+++ b/src/operations.test.js.md
@@ -10240,6 +10240,99 @@ Generated by [AVA](https://ava.li).
         ],
         verb: 'delete',
       },
+      {
+        operationId: 'listServiceInstancesForSite',
+        parameters: {
+          body: {},
+          path: {
+            site_id: {
+              in: 'path',
+              name: 'site_id',
+              required: true,
+              type: 'string',
+            },
+          },
+          query: {},
+        },
+        path: '/sites/{site_id}/service-instances',
+        responses: {
+          200: {
+            description: 'OK',
+            schema: {
+              items: {
+                properties: {
+                  auth_url: {
+                    type: 'string',
+                  },
+                  config: {
+                    type: 'object',
+                  },
+                  created_at: {
+                    format: 'dateTime',
+                    type: 'string',
+                  },
+                  env: {
+                    type: 'object',
+                  },
+                  external_attributes: {
+                    type: 'object',
+                  },
+                  id: {
+                    type: 'string',
+                  },
+                  service_name: {
+                    type: 'string',
+                  },
+                  service_path: {
+                    type: 'string',
+                  },
+                  service_slug: {
+                    type: 'string',
+                  },
+                  snippets: {
+                    items: {
+                      type: 'object',
+                    },
+                    type: 'array',
+                  },
+                  updated_at: {
+                    format: 'dateTime',
+                    type: 'string',
+                  },
+                  url: {
+                    type: 'string',
+                  },
+                },
+                type: 'object',
+              },
+              type: 'array',
+            },
+          },
+          default: {
+            description: 'error',
+            schema: {
+              properties: {
+                code: {
+                  format: 'int64',
+                  type: 'integer',
+                },
+                message: {
+                  type: 'string',
+                  'x-nullable': false,
+                },
+              },
+              required: [
+                'message',
+              ],
+              type: 'object',
+            },
+          },
+        },
+        tags: [
+          'serviceInstance',
+        ],
+        verb: 'get',
+      },
       {
         consumes: [
           'application/json',
@@ -10376,8 +10469,8 @@ Generated by [AVA](https://ava.li).
         },
         path: '/sites/{site_id}/services/{addon}/instances/{instance_id}',
         responses: {
-          201: {
-            description: 'Created',
+          200: {
+            description: 'OK',
             schema: {
               properties: {
                 auth_url: {
@@ -10491,7 +10584,7 @@ Generated by [AVA](https://ava.li).
         path: '/sites/{site_id}/services/{addon}/instances/{instance_id}',
         responses: {
           204: {
-            description: 'Created',
+            description: 'No Content',
           },
           default: {
             description: 'error',
diff --git a/src/operations.test.js.snap b/src/operations.test.js.snap
index 431ef6b..0a7d8f4 100644
Binary files a/src/operations.test.js.snap and b/src/operations.test.js.snap differ