diff --git a/composer.json b/composer.json
index 882e054..2dd665d 100644
--- a/composer.json
+++ b/composer.json
@@ -14,6 +14,9 @@
     "ipl/stdlib": "dev-main"
   },
   "autoload": {
+    "files": [
+      "src/pdo-driver-consts-forward-compat.php"
+    ],
     "psr-4": {
       "ipl\\Sql\\": "src"
     }
diff --git a/src/Adapter/Mysql.php b/src/Adapter/Mysql.php
index 7146579..52c8c0c 100644
--- a/src/Adapter/Mysql.php
+++ b/src/Adapter/Mysql.php
@@ -4,7 +4,7 @@
 
 use ipl\Sql\Config;
 use ipl\Sql\Connection;
-use PDO;
+use Pdo\Mysql as PdoMysql;
 
 class Mysql extends BaseAdapter
 {
@@ -22,40 +22,33 @@ public function setClientTimezone(Connection $db)
     public function getOptions(Config $config)
     {
         $options = parent::getOptions($config);
-        // In PHP 8.5+, driver-specific constants of the PDO class are deprecated,
-        // but the replacements are only available since php 8.4
-        if (version_compare(PHP_VERSION, '8.4.0', '<')) {
-            $mysqlConstantPrefix = 'PDO::MYSQL_ATTR_';
-        } else {
-            $mysqlConstantPrefix = 'Pdo\Mysql::ATTR_';
-        }
 
         if (! empty($config->useSsl)) {
             if (! empty($config->sslKey)) {
-                $options[constant($mysqlConstantPrefix . 'SSL_KEY')] = $config->sslKey;
+                $options[PdoMysql::ATTR_SSL_KEY] = $config->sslKey;
             }
 
             if (! empty($config->sslCert)) {
-                $options[constant($mysqlConstantPrefix . 'SSL_CERT')] = $config->sslCert;
+                $options[PdoMysql::ATTR_SSL_CERT] = $config->sslCert;
             }
 
             if (! empty($config->sslCa)) {
-                $options[constant($mysqlConstantPrefix . 'SSL_CA')] = $config->sslCa;
+                $options[PdoMysql::ATTR_SSL_CA] = $config->sslCa;
             }
 
             if (! empty($config->sslCapath)) {
-                $options[constant($mysqlConstantPrefix . 'SSL_CAPATH')] = $config->sslCapath;
+                $options[PdoMysql::ATTR_SSL_CAPATH] = $config->sslCapath;
             }
 
             if (! empty($config->sslCipher)) {
-                $options[constant($mysqlConstantPrefix . 'SSL_CIPHER')] = $config->sslCipher;
+                $options[PdoMysql::ATTR_SSL_CIPHER] = $config->sslCipher;
             }
 
             if (
-                defined($mysqlConstantPrefix . 'SSL_VERIFY_SERVER_CERT')
+                defined(PdoMysql::class . '::ATTR_SSL_VERIFY_SERVER_CERT')
                 && ! empty($config->sslDoNotVerifyServerCert)
             ) {
-                $options[constant($mysqlConstantPrefix . 'SSL_VERIFY_SERVER_CERT')] = false;
+                $options[PdoMysql::ATTR_SSL_VERIFY_SERVER_CERT] = false;
             }
         }
 
diff --git a/src/pdo-driver-consts-forward-compat.php b/src/pdo-driver-consts-forward-compat.php
new file mode 100644
index 0000000..3ba6ae8
--- /dev/null
+++ b/src/pdo-driver-consts-forward-compat.php
@@ -0,0 +1,62 @@
+<?php
+
+// phpcs:disable PSR1.Classes.ClassDeclaration.MultipleClasses
+
+namespace Pdo;
+
+use PDO;
+
+use const PHP_VERSION_ID;
+
+/*
+ * Forward compatibility shim for PDO MySQL driver constants.
+ *
+ * PHP 8.4 introduced driver-specific constants on Pdo\Mysql while older
+ * versions only expose PDO::MYSQL_* constants. This shim provides
+ * Pdo\Mysql::ATTR_* for PHP < 8.4.
+ */
+if (PHP_VERSION_ID < 80400 && extension_loaded('pdo_mysql')) {
+    /**
+     * Constants available with mysqlnd and libmysqlclient.
+     */
+    trait MysqlCommonConstants
+    {
+        public const ATTR_USE_BUFFERED_QUERY = PDO::MYSQL_ATTR_USE_BUFFERED_QUERY;
+        public const ATTR_LOCAL_INFILE = PDO::MYSQL_ATTR_LOCAL_INFILE;
+        public const ATTR_SSL_KEY = PDO::MYSQL_ATTR_SSL_KEY;
+        public const ATTR_SSL_CERT = PDO::MYSQL_ATTR_SSL_CERT;
+        public const ATTR_SSL_CA = PDO::MYSQL_ATTR_SSL_CA;
+        public const ATTR_SSL_CAPATH = PDO::MYSQL_ATTR_SSL_CAPATH;
+        public const ATTR_SSL_CIPHER = PDO::MYSQL_ATTR_SSL_CIPHER;
+        public const ATTR_INIT_COMMAND = PDO::MYSQL_ATTR_INIT_COMMAND;
+        public const ATTR_COMPRESS = PDO::MYSQL_ATTR_COMPRESS;
+        public const ATTR_DIRECT_QUERY = PDO::MYSQL_ATTR_DIRECT_QUERY;
+        public const ATTR_FOUND_ROWS = PDO::MYSQL_ATTR_FOUND_ROWS;
+        public const ATTR_IGNORE_SPACE = PDO::MYSQL_ATTR_IGNORE_SPACE;
+        public const ATTR_SERVER_PUBLIC_KEY = PDO::MYSQL_ATTR_SERVER_PUBLIC_KEY;
+        public const ATTR_MULTI_STATEMENTS = PDO::MYSQL_ATTR_MULTI_STATEMENTS;
+        public const ATTR_LOCAL_INFILE_DIRECTORY = PDO::MYSQL_ATTR_LOCAL_INFILE_DIRECTORY;
+    }
+
+    if (defined('PDO::MYSQL_ATTR_SSL_VERIFY_SERVER_CERT')) {
+        // mysqlnd variant: includes ATTR_SSL_VERIFY_SERVER_CERT.
+        // ATTR_READ_DEFAULT_* and ATTR_MAX_BUFFER_SIZE are not available with mysqlnd.
+        class Mysql
+        {
+            use MysqlCommonConstants;
+
+            public const ATTR_SSL_VERIFY_SERVER_CERT = PDO::MYSQL_ATTR_SSL_VERIFY_SERVER_CERT;
+        }
+    } else {
+        // non-mysqlnd variant: exposes ATTR_READ_DEFAULT_* and ATTR_MAX_BUFFER_SIZE.
+        // ATTR_SSL_VERIFY_SERVER_CERT is not available.
+        class Mysql
+        {
+            use MysqlCommonConstants;
+
+            public const ATTR_READ_DEFAULT_FILE = PDO::MYSQL_ATTR_READ_DEFAULT_FILE;
+            public const ATTR_READ_DEFAULT_GROUP = PDO::MYSQL_ATTR_READ_DEFAULT_GROUP;
+            public const ATTR_MAX_BUFFER_SIZE = PDO::MYSQL_ATTR_MAX_BUFFER_SIZE;
+        }
+    }
+}