diff --git a/build.gradle b/build.gradle
index a933dc9..abd4c31 100644
--- a/build.gradle
+++ b/build.gradle
@@ -37,6 +37,7 @@ dependencies {
 	testImplementation('org.springframework.boot:spring-boot-starter-test') {
 		exclude group: 'org.junit.vintage', module: 'junit-vintage-engine'
 	}
+	testImplementation 'nl.jqno.equalsverifier:equalsverifier:3.3'
 	testImplementation 'org.springframework.security:spring-security-test'
 	testImplementation 'com.h2database:h2:1.4.200'
 	// Fixes https://stackoverflow.com/a/60455550
diff --git a/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/ConfirmationToken.java b/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/ConfirmationToken.java
index 74028cb..7d73b41 100644
--- a/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/ConfirmationToken.java
+++ b/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/ConfirmationToken.java
@@ -9,7 +9,7 @@ import lombok.NonNull;
 
 @Data
 @Entity
-public class ConfirmationToken {
+public final class ConfirmationToken {
 
     @Id
     @GeneratedValue(strategy = GenerationType.AUTO)
@@ -55,7 +55,6 @@ public class ConfirmationToken {
         if (o == null || getClass() != o.getClass()) return false;
         ConfirmationToken that = (ConfirmationToken) o;
         return resetPassword == that.resetPassword
-                && Objects.equals(id, that.id)
                 && confirmToken.equals(that.confirmToken)
                 && createdDate.equals(that.createdDate)
                 && Objects.equals(user, that.user);
@@ -63,6 +62,6 @@ public class ConfirmationToken {
 
     @Override
     public int hashCode() {
-        return Objects.hash(id, confirmToken, createdDate, user, resetPassword);
+        return Objects.hash(confirmToken, createdDate, user, resetPassword);
     }
 }
diff --git a/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/User.java b/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/User.java
index fc575b5..95b30d1 100644
--- a/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/User.java
+++ b/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/User.java
@@ -6,6 +6,7 @@ import java.util.HashSet;
 import java.util.Objects;
 import java.util.Set;
 import javax.persistence.*;
+import lombok.EqualsAndHashCode;
 import lombok.Getter;
 import lombok.Setter;
 import lombok.ToString;
@@ -56,6 +57,7 @@ public class User {
     @GsonExclude
     @Getter
     @ToString.Exclude
+    @EqualsAndHashCode.Exclude
     private Set<User> guests = new HashSet<>();
 
     @ManyToMany(cascade = CascadeType.DETACH)
@@ -66,6 +68,7 @@ public class User {
     @GsonExclude
     @Getter
     @ToString.Exclude
+    @EqualsAndHashCode.Exclude
     private Set<User> hosts = new HashSet<>();
 
     /** Determines whether a guest can access security cameras */
diff --git a/src/test/java/ch/usi/inf/sa4/sanmarinoes/smarthut/controller/RegularLightControllerTests.java b/src/test/java/ch/usi/inf/sa4/sanmarinoes/smarthut/controller/RegularLightControllerTests.java
index 8d9e548..6b093d7 100644
--- a/src/test/java/ch/usi/inf/sa4/sanmarinoes/smarthut/controller/RegularLightControllerTests.java
+++ b/src/test/java/ch/usi/inf/sa4/sanmarinoes/smarthut/controller/RegularLightControllerTests.java
@@ -58,7 +58,7 @@ public class RegularLightControllerTests {
     @Test
     public void testGetAll() {
         when(regularLightRepository.findAll()).thenReturn(List.of());
-        assertThat(regularLightController.findAll().isEmpty());
+        assertThat(regularLightController.findAll()).isEmpty();
     }
 
     @Test
diff --git a/src/test/java/ch/usi/inf/sa4/sanmarinoes/smarthut/controller/RoomControllerTests.java b/src/test/java/ch/usi/inf/sa4/sanmarinoes/smarthut/controller/RoomControllerTests.java
index fb4e105..38cd498 100644
--- a/src/test/java/ch/usi/inf/sa4/sanmarinoes/smarthut/controller/RoomControllerTests.java
+++ b/src/test/java/ch/usi/inf/sa4/sanmarinoes/smarthut/controller/RoomControllerTests.java
@@ -171,6 +171,6 @@ public class RoomControllerTests {
     public void testGetDevices() throws NotFoundException {
         when(mockPrincipal.getName()).thenReturn("user");
         when(deviceService.findAll(2020L, 10L, "user")).thenReturn(List.of());
-        assertThat(roomController.getDevices(2020L, mockPrincipal, 10L));
+        assertThat(roomController.getDevices(2020L, mockPrincipal, 10L)).isNotNull();
     }
 }
diff --git a/src/test/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/ConfirmationTokenTests.java b/src/test/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/ConfirmationTokenTests.java
index 85e8c33..a46e35d 100644
--- a/src/test/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/ConfirmationTokenTests.java
+++ b/src/test/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/ConfirmationTokenTests.java
@@ -3,6 +3,7 @@ package ch.usi.inf.sa4.sanmarinoes.smarthut.models;
 import static org.junit.jupiter.api.Assertions.*;
 
 import java.util.Date;
+import nl.jqno.equalsverifier.EqualsVerifier;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
@@ -66,7 +67,7 @@ public class ConfirmationTokenTests {
     public void equals() {
         User user = new User();
         user.setName("Tizio Sempronio");
-        user.setId(42l);
+        user.setId(42L);
         user.setUsername("xXCoolUserNameXx");
         user.setEmail("realMail@service.ext");
         user.setPassword("alpaca");
@@ -75,4 +76,18 @@ public class ConfirmationTokenTests {
 
         assertNotEquals(t, token);
     }
+
+    @Test
+    public void testEqualsHashCode() {
+        final User u = new User();
+        u.setId(1L);
+        final User t = new User();
+        t.setId(2L);
+        EqualsVerifier.forClass(ConfirmationToken.class)
+                .withNonnullFields("createdDate")
+                .withNonnullFields("confirmToken")
+                .withPrefabValues(User.class, u, t)
+                .verify();
+        assertDoesNotThrow(() -> new ConfirmationToken().hashCode());
+    }
 }
diff --git a/src/test/java/ch/usi/inf/sa4/sanmarinoes/smarthut/service/DevicePopulationServiceTests.java b/src/test/java/ch/usi/inf/sa4/sanmarinoes/smarthut/service/DevicePopulationServiceTests.java
index a40ee49..3aa5d9c 100644
--- a/src/test/java/ch/usi/inf/sa4/sanmarinoes/smarthut/service/DevicePopulationServiceTests.java
+++ b/src/test/java/ch/usi/inf/sa4/sanmarinoes/smarthut/service/DevicePopulationServiceTests.java
@@ -1,5 +1,6 @@
 package ch.usi.inf.sa4.sanmarinoes.smarthut.service;
 
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
 import static org.mockito.Mockito.*;
 
 import ch.usi.inf.sa4.sanmarinoes.smarthut.models.*;
@@ -38,6 +39,6 @@ public class DevicePopulationServiceTests {
         list.add(t1);
         list.add(light2);
         doNothing().when(populationService).populateMeasuredTemperature(t1);
-        service.populateComputedFields(list);
+        assertDoesNotThrow(() -> service.populateComputedFields(list));
     }
 }