diff --git a/x-pack/plugins/fleet/common/types/rest_spec/epm.ts b/x-pack/plugins/fleet/common/types/rest_spec/epm.ts
index e8dee14e40b30..52eb071be995d 100644
--- a/x-pack/plugins/fleet/common/types/rest_spec/epm.ts
+++ b/x-pack/plugins/fleet/common/types/rest_spec/epm.ts
@@ -25,8 +25,6 @@ import type {
 
 export interface GetCategoriesRequest {
   query: {
-    // deprecated in 8.6
-    experimental?: boolean;
     prerelease?: boolean;
     include_policy_templates?: boolean;
   };
diff --git a/x-pack/plugins/fleet/server/types/rest_spec/epm.ts b/x-pack/plugins/fleet/server/types/rest_spec/epm.ts
index 227753541e81d..57ffe95621b63 100644
--- a/x-pack/plugins/fleet/server/types/rest_spec/epm.ts
+++ b/x-pack/plugins/fleet/server/types/rest_spec/epm.ts
@@ -12,7 +12,6 @@ import { ExperimentalDataStreamFeaturesSchema } from '../models/package_policy';
 export const GetCategoriesRequestSchema = {
   query: schema.object({
     prerelease: schema.maybe(schema.boolean()),
-    experimental: schema.maybe(schema.boolean()), // deprecated
     include_policy_templates: schema.maybe(schema.boolean()),
   }),
 };