diff --git a/src/value_ref/object_ref.ts b/src/value_ref/object_ref.ts
index 933ee6984d036718932503c678aa2f19c76758d5..19f79e7e143234a387dd497f42ced2ec870c4fae 100644
--- a/src/value_ref/object_ref.ts
+++ b/src/value_ref/object_ref.ts
@@ -97,6 +97,8 @@ export class ObjectReference implements IObjectReference {
      * instance de ParamValues référencée
      */
     public get referencedParamValues(): ParamValues {
+        if (this._referencedObject === undefined)
+            return undefined;
         return this._referencedObject.getReferencedParamValues(this._refDefinition);
     }
 
@@ -104,6 +106,8 @@ export class ObjectReference implements IObjectReference {
      * instance de Result référencée
      */
     public get referencedResult(): Result {
+        if (this._referencedObject === undefined)
+            return undefined;
         return this._referencedObject.getReferencedResult(this._refDefinition);
     }
 
@@ -111,6 +115,8 @@ export class ObjectReference implements IObjectReference {
      * instance de résultat complémentaire référencée
      */
     public get referencedExtraResult(): any {
+        if (this._referencedObject === undefined)
+            return undefined;
         return this._referencedObject.getReferencedExtraResult(this._refDefinition);
     }
 }