diff --git a/src/renderer/components/Experiment/Widgets/CustomEvaluationWidget.tsx b/src/renderer/components/Experiment/Widgets/CustomEvaluationWidget.tsx
index dcc4258da1a232971e6444a47db5b98744058bb8..80561250c75db8739d623638299f86fef1b27274 100644
--- a/src/renderer/components/Experiment/Widgets/CustomEvaluationWidget.tsx
+++ b/src/renderer/components/Experiment/Widgets/CustomEvaluationWidget.tsx
@@ -10,7 +10,7 @@ import {
 type EvaluationField = {
   name: string;
   expression: string;
-  return_type: 'boolean' | 'number';
+  return_type: string;
 };