diff --git a/src/main/java/com/example/demo/domain/TrainingPhase.java b/src/main/java/com/example/demo/domain/TrainingPhase.java
index 05e2b0166adcbfaf9bf3e4ed86fde8ffa3519372..49f789dff86838103413bfee5f6f74ebb518c046 100644
--- a/src/main/java/com/example/demo/domain/TrainingPhase.java
+++ b/src/main/java/com/example/demo/domain/TrainingPhase.java
@@ -5,18 +5,19 @@ import javax.persistence.Entity;
 import javax.persistence.FetchType;
 import javax.persistence.OneToMany;
 import javax.persistence.OrderBy;
+import java.util.ArrayList;
 import java.util.List;
 
 @Entity
 public class TrainingPhase extends AbstractPhase {
 
     private String estimatedDuration;
-    private Integer allowedCommands;
-    private Integer allowedWrongFlags;
+    private int allowedCommands;
+    private int allowedWrongFlags;
 
     @OrderBy
     @OneToMany(mappedBy = "trainingPhase", cascade = CascadeType.ALL, orphanRemoval = true, fetch = FetchType.LAZY)
-    private List<Task> tasks;
+    private List<Task> tasks = new ArrayList<>();
 
     @OrderBy
     @OneToMany(mappedBy = "trainingPhase", cascade = CascadeType.ALL, orphanRemoval = true, fetch = FetchType.LAZY)
@@ -30,19 +31,19 @@ public class TrainingPhase extends AbstractPhase {
         this.estimatedDuration = estimatedDuration;
     }
 
-    public Integer getAllowedCommands() {
+    public int getAllowedCommands() {
         return allowedCommands;
     }
 
-    public void setAllowedCommands(Integer allowedCommands) {
+    public void setAllowedCommands(int allowedCommands) {
         this.allowedCommands = allowedCommands;
     }
 
-    public Integer getAllowedWrongFlags() {
+    public int getAllowedWrongFlags() {
         return allowedWrongFlags;
     }
 
-    public void setAllowedWrongFlags(Integer allowedWrongFlags) {
+    public void setAllowedWrongFlags(int allowedWrongFlags) {
         this.allowedWrongFlags = allowedWrongFlags;
     }
 
diff --git a/src/main/java/com/example/demo/dto/TrainingPhaseDto.java b/src/main/java/com/example/demo/dto/TrainingPhaseDto.java
index 74454bb990583bc73b88e2f9afc126500c07925a..1da9d511f6de722ef748afd9694ae066128f1b47 100644
--- a/src/main/java/com/example/demo/dto/TrainingPhaseDto.java
+++ b/src/main/java/com/example/demo/dto/TrainingPhaseDto.java
@@ -1,13 +1,14 @@
 package com.example.demo.dto;
 
+import java.util.ArrayList;
 import java.util.List;
 
 public class TrainingPhaseDto extends AbstractPhaseDto {
 
     private String estimatedDuration;
-    private Integer allowedCommands;
-    private Integer allowedWrongFlags;
-    private List<TaskDto> tasks;
+    private int allowedCommands;
+    private int allowedWrongFlags;
+    private List<TaskDto> tasks = new ArrayList<>();
 
     private List<DecisionMatrixRowDto> decisionMatrix;
 
@@ -19,19 +20,19 @@ public class TrainingPhaseDto extends AbstractPhaseDto {
         this.estimatedDuration = estimatedDuration;
     }
 
-    public Integer getAllowedCommands() {
+    public int getAllowedCommands() {
         return allowedCommands;
     }
 
-    public void setAllowedCommands(Integer allowedCommands) {
+    public void setAllowedCommands(int allowedCommands) {
         this.allowedCommands = allowedCommands;
     }
 
-    public Integer getAllowedWrongFlags() {
+    public int getAllowedWrongFlags() {
         return allowedWrongFlags;
     }
 
-    public void setAllowedWrongFlags(Integer allowedWrongFlags) {
+    public void setAllowedWrongFlags(int allowedWrongFlags) {
         this.allowedWrongFlags = allowedWrongFlags;
     }