diff --git a/yaml/copy_columns.yaml b/yaml/copy_columns.yaml
index 65c2f00..ff8806c 100644
--- a/yaml/copy_columns.yaml
+++ b/yaml/copy_columns.yaml
@@ -13,6 +13,7 @@ operations:
   - name: Show diff between source and result
     command: diff
     input: ifc/office_level_0.ifc
+    target: ifc/office_level_columns.ifc
     output: office_level_columns.diff
     verbose: true