diff --git a/packages/@ama-sdk/core/src/clients/api-beacon-client.ts b/packages/@ama-sdk/core/src/clients/api-beacon-client.ts
index 61223358bc..a3e27180a2 100644
--- a/packages/@ama-sdk/core/src/clients/api-beacon-client.ts
+++ b/packages/@ama-sdk/core/src/clients/api-beacon-client.ts
@@ -25,7 +25,9 @@ const DEFAULT_OPTIONS: Omit<BaseApiBeaconClientOptions, 'basePath'> = {
  * Determine if the given value is a promise
  * @param value The value to test
  */
-const isPromise = <T>(value: T | Promise<T>): value is Promise<T> => value && typeof (value as any).then === 'function';
+// NOTE: the `extends unknown` is required for ESM build with TSC
+// eslint-disable-next-line @typescript-eslint/no-unnecessary-type-constraint
+const isPromise = <T extends unknown>(value: T | Promise<T>): value is Promise<T> => value && typeof (value as any).then === 'function';
 
 /**
  * The Beacon API client is an implementation of the API Client using the Navigator Beacon API.
diff --git a/packages/@ama-sdk/core/tsconfig.spec.json b/packages/@ama-sdk/core/tsconfig.spec.json
index d03b33ca19..8c0d0e6bf2 100644
--- a/packages/@ama-sdk/core/tsconfig.spec.json
+++ b/packages/@ama-sdk/core/tsconfig.spec.json
@@ -13,8 +13,7 @@
     "target": "ES2020"
   },
   "include": [
-    "./**/*.spec.ts",
-    "./schematics/ng-add/mocks/**/*.ts"
+    "./**/*.spec.ts"
   ],
   "exclude": [
   ],