diff --git a/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/Dimmable.java b/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/Dimmable.java
index bc093e0..e72cbf6 100644
--- a/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/Dimmable.java
+++ b/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/Dimmable.java
@@ -2,6 +2,7 @@ package ch.usi.inf.sa4.sanmarinoes.smarthut.models;
 
 import ch.usi.inf.sa4.sanmarinoes.smarthut.config.GsonExclude;
 import ch.usi.inf.sa4.sanmarinoes.smarthut.config.SocketGsonExclude;
+import java.util.HashSet;
 import java.util.Set;
 import javax.persistence.*;
 import javax.validation.constraints.Max;
@@ -19,7 +20,7 @@ public class Dimmable extends Switchable implements RangeTriggerable {
     @ManyToMany(mappedBy = "dimmables", cascade = CascadeType.DETACH)
     @GsonExclude
     @SocketGsonExclude
-    private Set<Dimmer> dimmers;
+    private Set<Dimmer> dimmers = new HashSet<>();
 
     /** The light intensity value. Goes from 0 (off) to 100 (on) */
     @NotNull