diff --git a/libraries/dbi/DBIExtension.lib.php b/libraries/dbi/DBIExtension.lib.php
new file mode 100644
index 0000000000..a5045f7941
--- /dev/null
+++ b/libraries/dbi/DBIExtension.lib.php
@@ -0,0 +1,28 @@
+<?php
+/**
+ * Contract for every database extension supported by phpMyAdmin
+ *
+ * @package PhpMyAdmin-DBI
+ */
+
+/**
+ * Defines PMA_MYSQL_CLIENT_API if it does not exist based
+ * on MySQL client version.
+ *
+ * @param string $version MySQL version string
+ *
+ * @return void
+ */
+function PMA_defineClientAPI($version)
+{
+    if (! defined('PMA_MYSQL_CLIENT_API')) {
+        $client_api = explode('.', $version);
+        define(
+        'PMA_MYSQL_CLIENT_API',
+        (int)sprintf(
+            '%d%02d%02d',
+            $client_api[0], $client_api[1], intval($client_api[2])
+        )
+        );
+    }
+}
diff --git a/libraries/dbi/DBIExtension.php b/libraries/dbi/DBIExtension.php
index 0800ddb081..a6d36f4a16 100644
--- a/libraries/dbi/DBIExtension.php
+++ b/libraries/dbi/DBIExtension.php
@@ -234,26 +234,3 @@ interface DBIExtension
      */
     public function fieldFlags($result, $i);
 }
-
-
-/**
- * Defines PMA_MYSQL_CLIENT_API if it does not exist based
- * on MySQL client version.
- *
- * @param string $version MySQL version string
- *
- * @return void
- */
-function PMA_defineClientAPI($version)
-{
-    if (! defined('PMA_MYSQL_CLIENT_API')) {
-        $client_api = explode('.', $version);
-        define(
-            'PMA_MYSQL_CLIENT_API',
-            (int)sprintf(
-                '%d%02d%02d',
-                $client_api[0], $client_api[1], intval($client_api[2])
-            )
-        );
-    }
-}
diff --git a/libraries/dbi/DBIMysqli.php b/libraries/dbi/DBIMysqli.php
index 0d9b9d533b..f5315433cc 100644
--- a/libraries/dbi/DBIMysqli.php
+++ b/libraries/dbi/DBIMysqli.php
@@ -8,7 +8,6 @@
  */
 namespace PMA\libraries\dbi;
 
-use mysqli_result;
 use PMA\libraries\DatabaseInterface;
 
 if (! defined('PHPMYADMIN')) {