diff --git a/src/fr/impl/ConfigurationImpl.java b/src/fr/impl/ConfigurationImpl.java
index f467cc0..ca763fe 100644
--- a/src/fr/impl/ConfigurationImpl.java
+++ b/src/fr/impl/ConfigurationImpl.java
@@ -6,11 +6,12 @@ import src.fr.api.CompatibilityManager;
 import src.fr.api.Configuration;
 import src.fr.api.Part;
 
+import java.util.HashSet;
 import java.util.Optional;
 import java.util.Set;
 
 public class ConfigurationImpl implements Configuration {
-    private Set<Part> selectedParts;
+    private Set<Part> selectedParts = new HashSet<Part> ();
     private CompatibilityManager compatibilityManager;
     private static int NB_CATEGORY = 4;