diff --git a/src/main/java/de/hmmh/pmt/db/Project.java b/src/main/java/de/hmmh/pmt/db/Project.java
index c66731a..0a70189 100644
--- a/src/main/java/de/hmmh/pmt/db/Project.java
+++ b/src/main/java/de/hmmh/pmt/db/Project.java
@@ -1,6 +1,9 @@
 package de.hmmh.pmt.db;
 
 import jakarta.persistence.*;
+import jakarta.validation.ConstraintViolation;
+import jakarta.validation.Validation;
+import jakarta.validation.Validator;
 import jakarta.validation.constraints.NotBlank;
 import jakarta.validation.constraints.NotNull;
 import jakarta.validation.constraints.Size;
@@ -10,6 +13,7 @@ import lombok.NoArgsConstructor;
 import lombok.Setter;
 
 import java.time.LocalDateTime;
+import java.util.Set;
 
 @NoArgsConstructor
 @AllArgsConstructor
@@ -46,7 +50,13 @@ public class Project {
 
 
     public boolean isValid() {
-        return plannedEnd.isAfter(start) && (realEnd == null || realEnd.isAfter(start));
+        Validator validator = Validation.buildDefaultValidatorFactory().getValidator();
+        Set<ConstraintViolation<Project>> violations = validator.validate(this);
+
+        return violations.isEmpty() &&
+               plannedEnd.isAfter(start) &&
+               (realEnd == null || realEnd.isAfter(start));
     }
+
 }