diff --git a/static/js/data.js b/static/js/data.js
index 8471d309..bca0db15 100644
--- a/static/js/data.js
+++ b/static/js/data.js
@@ -76,7 +76,7 @@ class excitationBase {
   }
 }
 class excitationValue extends excitationBase {
-  constructor(initial, final, value,Correction) {
+  constructor(initial, final, value,correction=null) {
     super(initial, final)
     this.value = value
     this.correction = correction