diff --git a/adminer/drivers/mysql.inc.php b/adminer/drivers/mysql.inc.php
index 3ea4704d..60f75209 100644
--- a/adminer/drivers/mysql.inc.php
+++ b/adminer/drivers/mysql.inc.php
@@ -236,20 +236,20 @@ if (!defined("DRIVER")) {
 
 			function connect($server, $username, $password) {
 				global $adminer;
-				$options = array(PDO::MYSQL_ATTR_LOCAL_INFILE => false);
+				$options = array(\PDO::MYSQL_ATTR_LOCAL_INFILE => false);
 				$ssl = $adminer->connectSsl();
 				if ($ssl) {
 					if ($ssl['key']) {
-						$options[PDO::MYSQL_ATTR_SSL_KEY] = $ssl['key'];
+						$options[\PDO::MYSQL_ATTR_SSL_KEY] = $ssl['key'];
 					}
 					if ($ssl['cert']) {
-						$options[PDO::MYSQL_ATTR_SSL_CERT] = $ssl['cert'];
+						$options[\PDO::MYSQL_ATTR_SSL_CERT] = $ssl['cert'];
 					}
 					if ($ssl['ca']) {
-						$options[PDO::MYSQL_ATTR_SSL_CA] = $ssl['ca'];
+						$options[\PDO::MYSQL_ATTR_SSL_CA] = $ssl['ca'];
 					}
 					if (isset($ssl['verify'])) {
-						$options[PDO::MYSQL_ATTR_SSL_VERIFY_SERVER_CERT] = $ssl['verify'];
+						$options[\PDO::MYSQL_ATTR_SSL_VERIFY_SERVER_CERT] = $ssl['verify'];
 					}
 				}
 				$this->dsn(
@@ -271,7 +271,7 @@ if (!defined("DRIVER")) {
 			}
 
 			function query($query, $unbuffered = false) {
-				$this->pdo->setAttribute(PDO::MYSQL_ATTR_USE_BUFFERED_QUERY, !$unbuffered);
+				$this->pdo->setAttribute(\PDO::MYSQL_ATTR_USE_BUFFERED_QUERY, !$unbuffered);
 				return parent::query($query, $unbuffered);
 			}
 		}
diff --git a/adminer/include/pdo.inc.php b/adminer/include/pdo.inc.php
index f03a9ed7..6791343c 100644
--- a/adminer/include/pdo.inc.php
+++ b/adminer/include/pdo.inc.php
@@ -15,14 +15,14 @@ if (extension_loaded('pdo')) {
 		}
 
 		function dsn($dsn, $username, $password, $options = array()) {
-			$options[PDO::ATTR_ERRMODE] = PDO::ERRMODE_SILENT;
-			$options[PDO::ATTR_STATEMENT_CLASS] = array('PdoDbStatement');
+			$options[\PDO::ATTR_ERRMODE] = \PDO::ERRMODE_SILENT;
+			$options[\PDO::ATTR_STATEMENT_CLASS] = array('Adminer\PdoDbStatement');
 			try {
-				$this->pdo = new PDO($dsn, $username, $password, $options);
+				$this->pdo = new \PDO($dsn, $username, $password, $options);
 			} catch (Exception $ex) {
 				auth_error(h($ex->getMessage()));
 			}
-			$this->server_info = @$this->pdo->getAttribute(PDO::ATTR_SERVER_VERSION);
+			$this->server_info = @$this->pdo->getAttribute(\PDO::ATTR_SERVER_VERSION);
 		}
 
 		/*abstract function select_db($database);*/
@@ -86,11 +86,11 @@ if (extension_loaded('pdo')) {
 		var $_offset = 0, $num_rows;
 
 		function fetch_assoc() {
-			return $this->fetch(PDO::FETCH_ASSOC);
+			return $this->fetch(\PDO::FETCH_ASSOC);
 		}
 
 		function fetch_row() {
-			return $this->fetch(PDO::FETCH_NUM);
+			return $this->fetch(\PDO::FETCH_NUM);
 		}
 
 		function fetch_field() {