diff --git a/layouts/partials/csv/render-table-header.html b/layouts/partials/csv/render-table-header.html
index edacdb7..0537328 100644
--- a/layouts/partials/csv/render-table-header.html
+++ b/layouts/partials/csv/render-table-header.html
@@ -18,7 +18,7 @@
   {{- /* column codeを利用する場合  */}}
   {{- if $useColumnCode }}
     {{- if eq $rowIndex (sub $head 1) }}
-      {{- $columnId := partial "csv/get-column-id.html" (dict "row" $rowData "index" $i) }}
+      {{- $columnId = partial "csv/get-column-id.html" (dict "row" $rowData "index" $i) }}
       {{ $cell = partial "csv/trim-column-id.html" $cell }}
     {{- end}}
   {{- end}}
@@ -42,4 +42,4 @@
 </tr>
   {{- end }}
 {{- end }}
-</thead>
\ No newline at end of file
+</thead>