diff --git a/google-cloud-storage/src/main/java/com/google/cloud/storage/transfermanager/TransferManagerImpl.java b/google-cloud-storage/src/main/java/com/google/cloud/storage/transfermanager/TransferManagerImpl.java
index 4bbbeb9393..5489c1c890 100644
--- a/google-cloud-storage/src/main/java/com/google/cloud/storage/transfermanager/TransferManagerImpl.java
+++ b/google-cloud-storage/src/main/java/com/google/cloud/storage/transfermanager/TransferManagerImpl.java
@@ -26,6 +26,7 @@
 import com.google.cloud.storage.BlobInfo;
 import com.google.cloud.storage.BlobWriteSessionConfigs;
 import com.google.cloud.storage.ParallelCompositeUploadBlobWriteSessionConfig;
+import com.google.cloud.storage.ParallelCompositeUploadBlobWriteSessionConfig.BufferAllocationStrategy;
 import com.google.cloud.storage.ParallelCompositeUploadBlobWriteSessionConfig.ExecutorSupplier;
 import com.google.cloud.storage.Storage;
 import com.google.cloud.storage.Storage.BlobWriteOption;
@@ -83,7 +84,11 @@ final class TransferManagerImpl implements TransferManager {
     if (transferManagerConfig.isAllowParallelCompositeUpload()) {
       ParallelCompositeUploadBlobWriteSessionConfig pcuConfig =
           BlobWriteSessionConfigs.parallelCompositeUpload()
-              .withExecutorSupplier(ExecutorSupplier.useExecutor(executor));
+              .withExecutorSupplier(ExecutorSupplier.useExecutor(executor))
+              .withBufferAllocationStrategy(
+                  BufferAllocationStrategy.fixedPool(
+                      transferManagerConfig.getMaxWorkers(),
+                      transferManagerConfig.getPerWorkerBufferSize()));
       storageOptions = storageOptions.toBuilder().setBlobWriteSessionConfig(pcuConfig).build();
     }
     this.pcuQueue = new ConcurrentLinkedDeque<>();
@@ -264,8 +269,13 @@ public void run() {
           return;
         }
 
-        UploadResult result = poll.callable.call();
-        poll.resultFuture.set(result);
+        try {
+          UploadResult result = poll.callable.call();
+          poll.resultFuture.set(result);
+        } catch (Throwable e) {
+          poll.resultFuture.setException(e);
+          throw e;
+        }
 
       } while (true);
     }