diff --git a/src/Entity/Subnet.php b/src/Entity/Subnet.php
index fe9dd2d..65d5794 100644
--- a/src/Entity/Subnet.php
+++ b/src/Entity/Subnet.php
@@ -19,10 +19,10 @@ class Subnet extends AbstractEntity
     #[ORM\Column(length: 255)]
     private ?string $ipAddress = null;
 
-    #[ORM\Column(length: 255)]
+    #[ORM\Column(length: 255, nullable: true)]
     private ?string $nextServer = null;
 
-    #[ORM\Column(length: 255)]
+    #[ORM\Column(length: 255, nullable: true)]
     private ?string $bootFileName = null;
 
     /**
@@ -76,7 +76,7 @@ class Subnet extends AbstractEntity
         return $this->nextServer;
     }
 
-    public function setNextServer(string $nextServer): static
+    public function setNextServer(?string $nextServer): static
     {
         $this->nextServer = $nextServer;
 
@@ -88,7 +88,7 @@ class Subnet extends AbstractEntity
         return $this->bootFileName;
     }
 
-    public function setBootFileName(string $bootFileName): static
+    public function setBootFileName(?string $bootFileName): static
     {
         $this->bootFileName = $bootFileName;