diff --git a/lib/private/Files/ObjectStore/S3.php b/lib/private/Files/ObjectStore/S3.php
index 76eee2bc96241..2d9119b5fc692 100644
--- a/lib/private/Files/ObjectStore/S3.php
+++ b/lib/private/Files/ObjectStore/S3.php
@@ -49,7 +49,7 @@ public function initiateMultipartUpload(string $urn): string {
 		$upload = $this->getConnection()->createMultipartUpload([
 			'Bucket' => $this->bucket,
 			'Key' => $urn,
-		]);
+		] + $this->getSSECParameters());
 		$uploadId = $upload->get('UploadId');
 		if ($uploadId === null) {
 			throw new Exception('No upload id returned');
@@ -65,7 +65,7 @@ public function uploadMultipartPart(string $urn, string $uploadId, int $partId,
 			'ContentLength' => $size,
 			'PartNumber' => $partId,
 			'UploadId' => $uploadId,
-		]);
+		] + $this->getSSECParameters());
 	}
 
 	public function getMultipartUploads(string $urn, string $uploadId): array {
@@ -80,12 +80,12 @@ public function getMultipartUploads(string $urn, string $uploadId): array {
 				'UploadId' => $uploadId,
 				'MaxParts' => 1000,
 				'PartNumberMarker' => $partNumberMarker
-			]);
+			] + $this->getSSECParameters());
 			$parts = array_merge($parts, $result->get('Parts') ?? []);
 			$isTruncated = $result->get('IsTruncated');
 			$partNumberMarker = $result->get('NextPartNumberMarker');
 		}
-		
+
 		return $parts;
 	}
 
@@ -95,7 +95,7 @@ public function completeMultipartUpload(string $urn, string $uploadId, array $re
 			'Key' => $urn,
 			'UploadId' => $uploadId,
 			'MultipartUpload' => ['Parts' => $result],
-		]);
+		] + $this->getSSECParameters());
 		$stat = $this->getConnection()->headObject([
 			'Bucket' => $this->bucket,
 			'Key' => $urn,