diff --git a/s3-tfvars-files.tf b/s3-tfvars-files.tf
index 2ee3ef3..5205777 100644
--- a/s3-tfvars-files.tf
+++ b/s3-tfvars-files.tf
@@ -1,8 +1,9 @@
 resource "aws_s3_object" "tfvar_file" {
   for_each = local.tfvars_files
 
-  bucket     = aws_s3_bucket.tfvars.id
-  key        = each.value["key"] == "" ? each.value["path"] : each.value["key"]
-  source     = each.value["path"]
-  kms_key_id = local.tfvars_kms_encryption ? aws_kms_key.tfvars[0].arn : null
+  bucket      = aws_s3_bucket.tfvars.id
+  key         = each.value["key"] == "" ? each.value["path"] : each.value["key"]
+  source      = each.value["path"]
+  source_hash = filemd5(each.value["path"])
+  kms_key_id  = local.tfvars_kms_encryption ? aws_kms_key.tfvars[0].arn : null
 }