diff --git a/module/rdd-utility.js b/module/rdd-utility.js
index 0c216f6b..f8739ae5 100644
--- a/module/rdd-utility.js
+++ b/module/rdd-utility.js
@@ -396,17 +396,21 @@ export class RdDUtility  {
   {
     let xp = 0;
     for (let troncList of competenceTroncs) {
-      let minNiveau = 15;
+      let minNiveau = 0;
       for (let troncName of troncList) {
         let comp = RdDUtility.findCompetence( competenceList, troncName);
-        minNiveau = (comp.data.niveau < minNiveau) ? comp.data.niveau : minNiveau; 
+        if (comp) {
+          minNiveau = Math.min(comp.data.niveau, minNiveau); 
+        }
       }
-      if ( minNiveau > 0 ) minNiveau = 0; // Clamp à 0, pour le tronc commun
+      minNiveau = Math.max(minNiveau, 0); // Clamp à 0, pour le tronc commun
       let minNiveauXP = competence_xp_par_niveau[minNiveau+10];
       xp += minNiveauXP;
       for (let troncName of troncList) {
         let comp = RdDUtility.findCompetence( competenceList, troncName);
-        xp += competence_xp_par_niveau[comp.data.niveau+10] - minNiveauXP;
+        if (comp){
+          xp += competence_xp_par_niveau[comp.data.niveau+10] - minNiveauXP;
+        } 
       }
     }
     return xp;