diff --git a/services-custom/s3-transfer-manager/src/main/java/software/amazon/awssdk/transfer/s3/internal/serialization/TransferManagerJsonUnmarshaller.java b/services-custom/s3-transfer-manager/src/main/java/software/amazon/awssdk/transfer/s3/internal/serialization/TransferManagerJsonUnmarshaller.java
index da61e48cf6c3..5650ebc528cf 100644
--- a/services-custom/s3-transfer-manager/src/main/java/software/amazon/awssdk/transfer/s3/internal/serialization/TransferManagerJsonUnmarshaller.java
+++ b/services-custom/s3-transfer-manager/src/main/java/software/amazon/awssdk/transfer/s3/internal/serialization/TransferManagerJsonUnmarshaller.java
@@ -19,6 +19,7 @@
 
 import java.math.BigDecimal;
 import java.time.Instant;
+import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;