diff --git a/packages/core/testing/src/before_each.ts b/packages/core/testing/src/before_each.ts
index 42425bfc66..f438935169 100644
--- a/packages/core/testing/src/before_each.ts
+++ b/packages/core/testing/src/before_each.ts
@@ -26,3 +26,7 @@ if (_global.beforeEach) {
     resetFakeAsyncZone();
   });
 }
+
+// TODO(juliemr): remove this, only used because we need to export something to have compilation
+// work.
+export const __core_private_testing_placeholder__ = '';