diff --git a/doc/release-notes/12358-enable-s3-multipart-upload.md b/doc/release-notes/12358-enable-s3-multipart-upload.md
new file mode 100644
index 00000000000..22365fbbaec
--- /dev/null
+++ b/doc/release-notes/12358-enable-s3-multipart-upload.md
@@ -0,0 +1 @@
+Fixed a defect that caused upload of files larger than 1G to fail silently for S3 storage, unless direct upload was used. 
\ No newline at end of file
diff --git a/src/main/java/edu/harvard/iq/dataverse/dataaccess/S3AccessIO.java b/src/main/java/edu/harvard/iq/dataverse/dataaccess/S3AccessIO.java
index cb5175bd354..6d3fe205639 100644
--- a/src/main/java/edu/harvard/iq/dataverse/dataaccess/S3AccessIO.java
+++ b/src/main/java/edu/harvard/iq/dataverse/dataaccess/S3AccessIO.java
@@ -1208,6 +1208,9 @@ private static S3AsyncClient getClient(String driverId) {
             // Create a builder for the S3AsyncClient
             S3AsyncClientBuilder s3CB = S3AsyncClient.builder().requestChecksumCalculation(RequestChecksumCalculation.WHEN_REQUIRED);
 
+            // Always enable multipart upload. It is only used when necessary
+            s3CB.multipartEnabled(true);
+
             // Create a custom HTTP client with the desired pool size
             Integer poolSize = Integer.getInteger("dataverse.files." + driverId + ".connection-pool-size", 256);
             Builder httpClientBuilder = NettyNioAsyncHttpClient.builder().maxConcurrency(poolSize);