diff --git a/compare-algorithms/src/components/SimplificationControl.js b/compare-algorithms/src/components/SimplificationControl.js
index 3bd3546..6f71fa3 100644
--- a/compare-algorithms/src/components/SimplificationControl.js
+++ b/compare-algorithms/src/components/SimplificationControl.js
@@ -6,7 +6,7 @@ import { RangeInput } from './RangeInput.js'
 
 import state from '../state.js'
 
-const FieldComponent = ({ field }) => {
+const FieldComponent = observer(({ field }) => {
   switch (field.type) {
     case 'range':
       let { name, id } = field
@@ -33,7 +33,7 @@ const FieldComponent = ({ field }) => {
     default:
       return <span>Error: Field type {field.type} not known.</span>
   }
-}
+})
 
 const Options = ({ fields }) => {
   return (