diff --git a/src/Db/Adapter/MysqlAdapter.php b/src/Db/Adapter/MysqlAdapter.php
index 76b71f4d..4351d3c7 100644
--- a/src/Db/Adapter/MysqlAdapter.php
+++ b/src/Db/Adapter/MysqlAdapter.php
@@ -305,7 +305,11 @@ protected function mapColumnData(array $data): array
                 $data['length'] = null;
             }
             $standardLengths = [TableSchema::LENGTH_TINY, TableSchema::LENGTH_MEDIUM, TableSchema::LENGTH_LONG];
-            if ($data['length'] !== null && !in_array($data['length'], $standardLengths, true)) {
+            if (
+                $data['length'] !== null &&
+                $data['length'] > TableSchema::LENGTH_TINY &&
+                !in_array($data['length'], $standardLengths, true)
+            ) {
                 foreach ($standardLengths as $bucket) {
                     if ($bucket < $data['length']) {
                         continue;
diff --git a/tests/TestCase/Db/Adapter/MysqlAdapterTest.php b/tests/TestCase/Db/Adapter/MysqlAdapterTest.php
index a12e765a..f0d3a3bc 100644
--- a/tests/TestCase/Db/Adapter/MysqlAdapterTest.php
+++ b/tests/TestCase/Db/Adapter/MysqlAdapterTest.php
@@ -17,6 +17,7 @@
 use Migrations\Db\Table;
 use Migrations\Db\Table\Column;
 use Migrations\Db\Table\ForeignKey;
+use Migrations\Db\Table\Index;
 use PDO;
 use PDOException;
 use PHPUnit\Framework\Attributes\DataProvider;
@@ -337,6 +338,27 @@ public function testCreateTableWithPrimaryKeyAsBinaryUuid()
         $this->assertTrue($this->adapter->hasColumn('ztable', 'user_id'));
     }
 
+    public function testCreateTableBinaryLengthWithIndex()
+    {
+        $table = new Table('ntable', [], $this->adapter);
+        $table
+            ->addColumn('file', 'binary', [
+                'default' => null,
+                'length' => 20,
+                'null' => true,
+            ])
+            ->addIndex(
+                (new Index())
+                    ->setColumns(['file'])
+                    ->setName('file_idx')
+                    ->setType('unique'),
+            )
+            ->create();
+        $this->assertTrue($this->adapter->hasColumn('ntable', 'id'));
+        $this->assertTrue($this->adapter->hasColumn('ntable', 'file'));
+        $this->assertTrue($this->adapter->hasIndex('ntable', 'file'));
+    }
+
     /**
      * @return void
      */
@@ -1071,8 +1093,11 @@ public static function binaryToBlobAutomaticConversionData()
         return [
             // When creating binary with limit > 255, MySQL auto-converts to BLOB
             // input limit, expected SQL type name, expected column limit after round-trip
+            // For values smaller than 255, we preserve the length.
             [null, 'blob', MysqlAdapter::BLOB_REGULAR], // binary(null) becomes BLOB
-            [64, 'tinyblob', MysqlAdapter::BLOB_TINY], // binary(64) becomes TINYBLOB
+            [64, 'binary', 64], // binary(64) becomes binary(64)
+            [254, 'binary', 254], // binary(254) becomes binary(254)
+            [255, 'tinyblob', MysqlAdapter::BLOB_TINY], // binary(255) becomes TINYBLOB
             [MysqlAdapter::BLOB_REGULAR - 20, 'mediumblob', MysqlAdapter::BLOB_MEDIUM],
             [MysqlAdapter::BLOB_REGULAR, 'blob', MysqlAdapter::BLOB_REGULAR],
             [MysqlAdapter::BLOB_REGULAR + 20, 'mediumblob', MysqlAdapter::BLOB_MEDIUM],
@@ -1099,8 +1124,11 @@ public static function varbinaryToBlobAutomaticConversionData()
         return [
             // When creating varbinary with limit > 255, MySQL auto-converts to BLOB
             // input limit, expected SQL type name, expected column limit after round-trip
+            // For values smaller than 255, we preserve the length.
             [null, 'blob', MysqlAdapter::BLOB_REGULAR], // varbinary(null) becomes BLOB
-            [64, 'tinyblob', MysqlAdapter::BLOB_TINY], // varbinary(64) becomes TINYBLOB
+            [64, 'binary', 64], // varbinary(64) becomes binary(64)
+            [254, 'binary', 254], // varbinary(254) becomes binary(254)
+            [255, 'tinyblob', MysqlAdapter::BLOB_TINY], // varbinary(255) becomes TINYBLOB
             [MysqlAdapter::BLOB_REGULAR - 20, 'mediumblob', MysqlAdapter::BLOB_MEDIUM],
             [MysqlAdapter::BLOB_REGULAR, 'blob', MysqlAdapter::BLOB_REGULAR],
             [MysqlAdapter::BLOB_REGULAR + 20, 'mediumblob', MysqlAdapter::BLOB_MEDIUM],