diff --git a/x-pack/test_serverless/api_integration/test_suites/observability/ai_assistant/tests/knowledge_base/knowledge_base.spec.ts b/x-pack/test_serverless/api_integration/test_suites/observability/ai_assistant/tests/knowledge_base/knowledge_base.spec.ts
index 9499280c9786a..20ccce8203ce5 100644
--- a/x-pack/test_serverless/api_integration/test_suites/observability/ai_assistant/tests/knowledge_base/knowledge_base.spec.ts
+++ b/x-pack/test_serverless/api_integration/test_suites/observability/ai_assistant/tests/knowledge_base/knowledge_base.spec.ts
@@ -22,6 +22,9 @@ export default function ApiTest({ getService }: FtrProviderContext) {
   const observabilityAIAssistantAPIClient = getService('observabilityAIAssistantAPIClient');
 
   describe('Knowledge base', function () {
+    // Fails on MKI: https://github.com/elastic/kibana/issues/205581
+    this.tags(['failsOnMKI']);
+
     before(async () => {
       await createKnowledgeBaseModel(ml);