diff --git a/src/plugins/apm_oss/server/mocks.ts b/src/plugins/apm_oss/server/mocks.ts
index 68cb00440802e..30904ab30d865 100644
--- a/src/plugins/apm_oss/server/mocks.ts
+++ b/src/plugins/apm_oss/server/mocks.ts
@@ -24,6 +24,7 @@ import { APMOSSPluginSetup } from './plugin';
 const apmStar = 'apm-*';
 
 const defaultConfig = {
+  enabled: true,
   errorIndices: apmStar,
   indexPattern: apmStar,
   metricsIndices: apmStar,
diff --git a/x-pack/plugins/upgrade_assistant/server/lib/apm/extract_index_patterns.ts b/x-pack/plugins/upgrade_assistant/server/lib/apm/extract_index_patterns.ts
index dd142dded6e71..f45ebf60f0264 100644
--- a/x-pack/plugins/upgrade_assistant/server/lib/apm/extract_index_patterns.ts
+++ b/x-pack/plugins/upgrade_assistant/server/lib/apm/extract_index_patterns.ts
@@ -3,16 +3,28 @@
  * or more contributor license agreements. Licensed under the Elastic License;
  * you may not use this file except in compliance with the Elastic License.
  */
-import { uniq } from 'lodash';
+import { uniq, pick } from 'lodash';
+import { APMOSSConfig } from '../../../../../../src/plugins/apm_oss/server';
 
-export const extractIndexPatterns = (apmConfig: Record<string, string>): string[] =>
-  uniq(
-    [
-      'sourcemapIndices',
-      'errorIndices',
-      'transactionIndices',
-      'spanIndices',
-      'metricsIndices',
-      'onboardingIndices',
-    ].map(type => apmConfig[type]!)
-  );
+type APMIndexConfig = Pick<
+  APMOSSConfig,
+  | 'sourcemapIndices'
+  | 'errorIndices'
+  | 'transactionIndices'
+  | 'spanIndices'
+  | 'metricsIndices'
+  | 'onboardingIndices'
+>;
+
+export const extractIndexPatterns = (apmConfig: APMOSSConfig): string[] => {
+  const indexConfigs = pick<APMIndexConfig, APMOSSConfig>(apmConfig, [
+    'sourcemapIndices',
+    'errorIndices',
+    'transactionIndices',
+    'spanIndices',
+    'metricsIndices',
+    'onboardingIndices',
+  ]);
+
+  return uniq(Object.values(indexConfigs));
+};