diff --git a/x-pack/plugins/ml/kibana.json b/x-pack/plugins/ml/kibana.json
index e944af6821c0b..3bdf859731438 100644
--- a/x-pack/plugins/ml/kibana.json
+++ b/x-pack/plugins/ml/kibana.json
@@ -3,7 +3,8 @@
   "version": "0.0.1",
   "kibanaVersion": "kibana",
   "configPath": ["ml"],
-  "requiredPlugins": ["cloud", "features", "home", "licensing", "security", "spaces", "usageCollection"],
+  "requiredPlugins": ["cloud", "features", "home", "licensing", "usageCollection"],
+  "optionalPlugins": ["security", "spaces"],
   "server": true,
   "ui": false
 }
diff --git a/x-pack/plugins/ml/server/plugin.ts b/x-pack/plugins/ml/server/plugin.ts
index a3f5733738432..547d3f8ab06cb 100644
--- a/x-pack/plugins/ml/server/plugin.ts
+++ b/x-pack/plugins/ml/server/plugin.ts
@@ -117,7 +117,7 @@ export class MlServerPlugin {
     resultsServiceRoutes(routeInit);
     jobValidationRoutes(routeInit, this.version);
     systemRoutes(routeInit, {
-      spacesPlugin: plugins.spaces,
+      spaces: plugins.spaces,
       cloud: plugins.cloud,
     });
     initMlServerLog({ log: this.log });
diff --git a/x-pack/plugins/ml/server/routes/annotations.ts b/x-pack/plugins/ml/server/routes/annotations.ts
index 16483bf8b887e..c481fb8698855 100644
--- a/x-pack/plugins/ml/server/routes/annotations.ts
+++ b/x-pack/plugins/ml/server/routes/annotations.ts
@@ -36,7 +36,7 @@ function getAnnotationsFeatureUnavailableErrorMessage() {
  */
 export function annotationRoutes(
   { router, mlLicense }: RouteInitialization,
-  securityPlugin: SecurityPluginSetup
+  securityPlugin?: SecurityPluginSetup
 ) {
   /**
    * @apiGroup Annotations
@@ -101,9 +101,12 @@ export function annotationRoutes(
         }
 
         const { indexAnnotation } = annotationServiceProvider(context);
-        const user = securityPlugin.authc.getCurrentUser(request) || {};
+
+        const currentUser =
+          securityPlugin !== undefined ? securityPlugin.authc.getCurrentUser(request) : {};
         // @ts-ignore username doesn't exist on {}
-        const resp = await indexAnnotation(request.body, user.username || ANNOTATION_USER_UNKNOWN);
+        const username = currentUser?.username ?? ANNOTATION_USER_UNKNOWN;
+        const resp = await indexAnnotation(request.body, username);
 
         return response.ok({
           body: resp,
diff --git a/x-pack/plugins/ml/server/routes/system.ts b/x-pack/plugins/ml/server/routes/system.ts
index a0d7d312c04d4..2a0a760e94f79 100644
--- a/x-pack/plugins/ml/server/routes/system.ts
+++ b/x-pack/plugins/ml/server/routes/system.ts
@@ -19,7 +19,7 @@ import { RouteInitialization, SystemRouteDeps } from '../types';
  */
 export function systemRoutes(
   { router, mlLicense }: RouteInitialization,
-  { spacesPlugin, cloud }: SystemRouteDeps
+  { spaces, cloud }: SystemRouteDeps
 ) {
   async function getNodeCount(context: RequestHandlerContext) {
     const filterPath = 'nodes.*.attributes';
@@ -120,8 +120,8 @@ export function systemRoutes(
         const ignoreSpaces = request.query && request.query.ignoreSpaces === 'true';
         // if spaces is disabled force isMlEnabledInSpace to be true
         const { isMlEnabledInSpace } =
-          spacesPlugin !== undefined
-            ? spacesUtilsProvider(spacesPlugin, (request as unknown) as Request)
+          spaces !== undefined
+            ? spacesUtilsProvider(spaces, (request as unknown) as Request)
             : { isMlEnabledInSpace: async () => true };
 
         const { getPrivileges } = privilegesProvider(
diff --git a/x-pack/plugins/ml/server/types.ts b/x-pack/plugins/ml/server/types.ts
index aeb4c505ec55e..def8a1e5fa649 100644
--- a/x-pack/plugins/ml/server/types.ts
+++ b/x-pack/plugins/ml/server/types.ts
@@ -25,7 +25,7 @@ export interface LicenseCheckResult {
 
 export interface SystemRouteDeps {
   cloud: CloudSetup;
-  spacesPlugin: SpacesPluginSetup;
+  spaces?: SpacesPluginSetup;
 }
 
 export interface PluginsSetup {
@@ -33,8 +33,8 @@ export interface PluginsSetup {
   features: FeaturesPluginSetup;
   home: HomeServerPluginSetup;
   licensing: LicensingPluginSetup;
-  security: SecurityPluginSetup;
-  spaces: SpacesPluginSetup;
+  security?: SecurityPluginSetup;
+  spaces?: SpacesPluginSetup;
   usageCollection: UsageCollectionSetup;
 }