diff --git a/tests/Migrations/BaseTest.php b/tests/Migrations/BaseTest.php
index 05796b1..7627e74 100644
--- a/tests/Migrations/BaseTest.php
+++ b/tests/Migrations/BaseTest.php
@@ -205,6 +205,10 @@ public function getDriver(): Driver
         return static::$driverCache[static::DRIVER] = $this->driver;
     }
 
+    /**
+     * @param string $directory
+     * @return AbstractTable[]
+     */
     protected function migrate(string $directory): array
     {
         $tokenizer = new Tokenizer(new TokenizerConfig([
diff --git a/tests/Migrations/Fixtures/Alter/PrimaryToBigint.php b/tests/Migrations/Fixtures/Alter/PrimaryToBigint.php
new file mode 100644
index 0000000..daa10d6
--- /dev/null
+++ b/tests/Migrations/Fixtures/Alter/PrimaryToBigint.php
@@ -0,0 +1,17 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Cycle\Migrations\Tests\Fixtures\Alter;
+
+/**
+ * @Entity
+ */
+class PrimaryToBigint
+{
+    /**
+     * @Column(type=bigint, primary=true)
+     * @var int
+     */
+    protected $id;
+}
diff --git a/tests/Migrations/Fixtures/Init/PrimaryToBigint.php b/tests/Migrations/Fixtures/Init/PrimaryToBigint.php
new file mode 100644
index 0000000..f30cdd9
--- /dev/null
+++ b/tests/Migrations/Fixtures/Init/PrimaryToBigint.php
@@ -0,0 +1,17 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Cycle\Migrations\Tests\Fixtures\Init;
+
+/**
+ * @Entity
+ */
+class PrimaryToBigint
+{
+    /**
+     * @Column(type=primary)
+     * @var int
+     */
+    protected $id;
+}
diff --git a/tests/Migrations/ReflectTest.php b/tests/Migrations/ReflectTest.php
index 0bfd02d..d092e93 100644
--- a/tests/Migrations/ReflectTest.php
+++ b/tests/Migrations/ReflectTest.php
@@ -40,6 +40,9 @@ public function testNoChanges(): void
         $this->assertCount(2, $this->migrator->getMigrations());
     }
 
+    /**
+     * @throws \Throwable
+     */
     public function testAlter(): void
     {
         $tables = $this->migrate(__DIR__ . '/Fixtures/Init');