diff --git a/src/app/formulaire/ngparam.ts b/src/app/formulaire/ngparam.ts
index 4c464642c9cabc6df1ce2be43af6b85eda8f0bd5..c60586b3bba9c6dfd29095b4bbf2d8aaca193a93 100644
--- a/src/app/formulaire/ngparam.ts
+++ b/src/app/formulaire/ngparam.ts
@@ -253,9 +253,12 @@ export class NgParameter extends InputField {
 
             case ParamRadioConfig.CAL:
                 return true;
+
+            case undefined:
+                return false;
         }
 
-        throw "NgParameter.isValid() : valeur de ParamRadioConfig non prise en compte";
+        throw new Error(`"NgParameter.isValid() : valeur de ParamRadioConfig '${this.radioState}' (radioState) non prise en compte`);
     }
 
     private static getRadioConfig(s: string) {