diff --git a/interop-testing/src/main/java/io/grpc/testing/integration/AbstractTransportTest.java b/interop-testing/src/main/java/io/grpc/testing/integration/AbstractTransportTest.java
index 4b35c2e1b5..a4f89b9afe 100644
--- a/interop-testing/src/main/java/io/grpc/testing/integration/AbstractTransportTest.java
+++ b/interop-testing/src/main/java/io/grpc/testing/integration/AbstractTransportTest.java
@@ -711,7 +711,7 @@ public abstract class AbstractTransportTest {
       throws Exception {
     // cast to ServiceAccountCredentials to double-check the right type of object was created.
     GoogleCredentials credentials =
-        (ServiceAccountCredentials) GoogleCredentials.fromStream(credentialsStream);
+        ServiceAccountCredentials.class.cast(GoogleCredentials.fromStream(credentialsStream));
     credentials = credentials.createScoped(Arrays.<String>asList(authScope));
     TestServiceGrpc.TestServiceBlockingStub stub = blockingStub
         .withInterceptors(new ClientAuthInterceptor(credentials, testServiceExecutor));