diff --git a/terraform/deployments/opensearch/s3.tf b/terraform/deployments/opensearch/s3.tf
index 135f0542b..e1c95d7e8 100644
--- a/terraform/deployments/opensearch/s3.tf
+++ b/terraform/deployments/opensearch/s3.tf
@@ -27,7 +27,7 @@ resource "aws_s3_bucket_server_side_encryption_configuration" "opensearch_snapsh
   bucket = aws_s3_bucket.opensearch_snapshot.id
   rule {
     apply_server_side_encryption_by_default {
-      sse_algorithm = "aws:kms"
+      sse_algorithm = "AES256"
     }
   }
 }