diff --git a/java/google/registry/flows/domain/DomainTransferApproveFlow.java b/java/google/registry/flows/domain/DomainTransferApproveFlow.java
index a2cf9bc56..1faa64560 100644
--- a/java/google/registry/flows/domain/DomainTransferApproveFlow.java
+++ b/java/google/registry/flows/domain/DomainTransferApproveFlow.java
@@ -176,7 +176,7 @@ public final class DomainTransferApproveFlow implements TransactionalFlow {
                 (billingEvent.isPresent())
                     ? ImmutableSet.of(
                         GracePeriod.forBillingEvent(GracePeriodStatus.TRANSFER, billingEvent.get()))
-                    : ImmutableSet.of())
+                    : ImmutableSet.<GracePeriod>of())
             .build();
     // Create a poll message for the gaining client.
     PollMessage gainingClientPollMessage = createGainingTransferPollMessage(