diff --git a/src/customCategory.js b/src/customCategory.js
index 6dd8512d..63d89c7a 100644
--- a/src/customCategory.js
+++ b/src/customCategory.js
@@ -454,7 +454,7 @@ function customCategoryTestCompile (data) {
 
   let template
   try {
-    template = OverpassLayer.twig.twig({ data })
+    template = OverpassLayer.twig.twig({ data, rethrow: true })
   } catch (e) {
     return e
   }