diff --git a/lib/Capabilities.php b/lib/Capabilities.php
index 4996685b..c2ecc80e 100644
--- a/lib/Capabilities.php
+++ b/lib/Capabilities.php
@@ -19,7 +19,12 @@ public function __construct(
 	}
 
 	/**
-	 * @return array<string, array<string, bool|string>>
+	 * @return array{
+	 *     assistant: array{
+	 *         version: string,
+	 *         enabled?: bool
+	 *     }
+	 * }
 	 */
 	public function getCapabilities(): array {
 		$appVersion = $this->appManager->getAppVersion(Application::APP_ID);
diff --git a/openapi.json b/openapi.json
index b3a53e3c..800b227d 100644
--- a/openapi.json
+++ b/openapi.json
@@ -109,17 +109,23 @@
             },
             "PublicCapabilities": {
                 "type": "object",
-                "additionalProperties": {
-                    "type": "object",
-                    "additionalProperties": {
-                        "oneOf": [
-                            {
-                                "type": "boolean"
-                            },
-                            {
+                "required": [
+                    "assistant"
+                ],
+                "properties": {
+                    "assistant": {
+                        "type": "object",
+                        "required": [
+                            "version"
+                        ],
+                        "properties": {
+                            "version": {
                                 "type": "string"
+                            },
+                            "enabled": {
+                                "type": "boolean"
                             }
-                        ]
+                        }
                     }
                 }
             },