diff --git a/modules/workflows.nix b/modules/workflows.nix
index 38048cf..df8eb9d 100644
--- a/modules/workflows.nix
+++ b/modules/workflows.nix
@@ -60,11 +60,11 @@ let
       ''
         json2yaml "$valuePath" out
         cat "$headerPath" out > "$out"
-      ''
-    + (optionalString buildCheck ''
-      # Check that the workflow is valid
-      cd "${rootSrc}" && action-validator "$out"
-    '');
+        ${optionalString buildCheck ''
+          # Check that the workflow is valid
+          cd "${rootSrc}" && action-validator "$out"
+        ''}
+      '';
 
   install =
     name: value: