diff --git a/Sources/DiscogsService/openapi.yaml b/Sources/DiscogsService/openapi.yaml
index 66caee425..06eaf4956 100644
--- a/Sources/DiscogsService/openapi.yaml
+++ b/Sources/DiscogsService/openapi.yaml
@@ -1337,6 +1337,46 @@ paths:
           $ref: '#/components/responses/NotFound'
         '500':
           $ref: '#/components/responses/InternalError'
+  /users/{username}/collection/folders/{folder_id}/releases/{release_id}:
+    post:
+      tags:
+        - User Collection
+      summary: Add a release to a collection folder of a user.
+      description: |
+        Adds a release to a collection folder of a user.
+
+        > important: A `folder_id` must not be `0`, so it is possible to use the identifier `1` for the *Uncategorized* folder.
+
+        This endpoint requires authentication as the collection owner.
+      operationId: postReleaseToCollectionFolder
+      parameters:
+        - $ref: '#/components/parameters/Username'
+        - $ref: '#/components/parameters/FolderId'
+        - $ref: '#/components/parameters/ReleaseId'
+      security:
+        - ConsumerKeySecret: []
+        - UserToken: []
+        - OAuth: []
+      responses:
+        '201':
+          description: Successfully added a specific release into a collection folder of a user.
+          headers:
+            X-Discogs-RateLimit:
+              $ref: '#/components/headers/RateLimit'
+            X-Discogs-RateLimit-Used:
+              $ref: '#/components/headers/RateLimitUsed'
+            X-Discogs-RateLimit-Remaining:
+              $ref: '#/components/headers/RateLimitRemaining'
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/ReleaseInstance'
+        '403':
+          $ref: '#/components/responses/NotAccessable'
+        '404':
+          $ref: '#/components/responses/NotFound'
+        '500':
+          $ref: '#/components/responses/InternalError'
 components:
   headers:
     Link:
@@ -2329,6 +2369,21 @@ components:
         - instance_id
         - date_added
         - rating
+    ReleaseInstance:
+      description: A type that represents an instace of a release.
+      type: object
+      properties:
+        instance_id:
+          description: An identifier of a release instance.
+          type: integer
+          readOnly: true
+        resource_url:
+          description: A URI resource of a release instance.
+          type: string
+          format: uri
+      required:
+        - instance_id
+        - resource_url
     ReleaseFormat:
       description: A type that represents a format of a release.
       type: object