diff --git a/tests/Fixtures/Blog/PrimaryKey.php b/tests/Fixtures/Blog/PrimaryKey.php
index 210d934..d333495 100644
--- a/tests/Fixtures/Blog/PrimaryKey.php
+++ b/tests/Fixtures/Blog/PrimaryKey.php
@@ -3,13 +3,13 @@
 namespace ShipMonkTests\DoctrineEntityPreloader\Fixtures\Blog;
 
 use function base64_encode;
-use function random_int;
 
 class PrimaryKey
 {
 
     public const DOCTRINE_TYPE_NAME = 'primary_key';
-    public const LENGTH_BYTES = 4;
+
+    private static int $autoIncrement = 0;
 
     private int $data;
 
@@ -20,10 +20,7 @@ public function __construct(int $data)
 
     public static function new(): self
     {
-        $bits = self::LENGTH_BYTES * 8;
-        $maxValue = (1 << $bits) - 1;
-
-        return new self(random_int(0, $maxValue));
+        return new self(self::$autoIncrement++);
     }
 
     public function getData(): int
diff --git a/tests/Fixtures/Blog/Type/PrimaryKeyBinaryType.php b/tests/Fixtures/Blog/Type/PrimaryKeyBinaryType.php
index b43e9a3..cd8f601 100644
--- a/tests/Fixtures/Blog/Type/PrimaryKeyBinaryType.php
+++ b/tests/Fixtures/Blog/Type/PrimaryKeyBinaryType.php
@@ -56,7 +56,7 @@ public function getSQLDeclaration(
     ): string
     {
         return $platform->getBinaryTypeDeclarationSQL([
-            'length' => PrimaryKey::LENGTH_BYTES,
+            'length' => 4,
             'fixed' => true,
         ]);
     }