diff --git a/ext/mysqli/mysqli.c b/ext/mysqli/mysqli.c
index a8a75eff70863..dddb53585f14e 100644
--- a/ext/mysqli/mysqli.c
+++ b/ext/mysqli/mysqli.c
@@ -424,6 +424,19 @@ static const MYSQLND_REVERSE_API mysqli_reverse_api = {
 	mysqli_convert_zv_to_mysqlnd
 };
 
+static PHP_INI_MH(OnUpdateDefaultPort)
+{
+	zend_long value = ZEND_ATOL(ZSTR_VAL(new_value));
+
+	if (value < 0 || value > USHRT_MAX) {
+		return FAILURE;
+	}
+
+	MyG(default_port) = (unsigned short)value;
+
+	return SUCCESS;
+}
+
 /* {{{ PHP_INI_BEGIN */
 PHP_INI_BEGIN()
 	STD_PHP_INI_ENTRY_EX("mysqli.max_links",			"-1",	PHP_INI_SYSTEM,		OnUpdateLong,		max_links,			zend_mysqli_globals,		mysqli_globals, display_link_numbers)
@@ -433,7 +446,7 @@ PHP_INI_BEGIN()
 	STD_PHP_INI_ENTRY("mysqli.default_host",			NULL,	PHP_INI_ALL,		OnUpdateString,		default_host,		zend_mysqli_globals,		mysqli_globals)
 	STD_PHP_INI_ENTRY("mysqli.default_user",			NULL,	PHP_INI_ALL,		OnUpdateString,		default_user,		zend_mysqli_globals,		mysqli_globals)
 	STD_PHP_INI_ENTRY("mysqli.default_pw",				NULL,	PHP_INI_ALL,		OnUpdateString,		default_pw,			zend_mysqli_globals,		mysqli_globals)
-	STD_PHP_INI_ENTRY("mysqli.default_port",			"3306",	PHP_INI_ALL,		OnUpdateLong,		default_port,		zend_mysqli_globals,		mysqli_globals)
+	STD_PHP_INI_ENTRY("mysqli.default_port",			"3306",	PHP_INI_ALL,		OnUpdateDefaultPort,		default_port,		zend_mysqli_globals,		mysqli_globals)
 #ifdef PHP_MYSQL_UNIX_SOCK_ADDR
 	STD_PHP_INI_ENTRY("mysqli.default_socket",			MYSQL_UNIX_ADDR,PHP_INI_ALL,OnUpdateStringUnempty,	default_socket,	zend_mysqli_globals,		mysqli_globals)
 #else
diff --git a/ext/mysqli/php_mysqli_structs.h b/ext/mysqli/php_mysqli_structs.h
index c155281c8e4bc..2daa5af932882 100644
--- a/ext/mysqli/php_mysqli_structs.h
+++ b/ext/mysqli/php_mysqli_structs.h
@@ -236,21 +236,21 @@ extern void php_mysqli_fetch_into_hash_aux(zval *return_value, MYSQL_RES * resul
 
 
 ZEND_BEGIN_MODULE_GLOBALS(mysqli)
-	zend_long			num_links;
-	zend_long			max_links;
-	zend_long 			num_active_persistent;
-	zend_long 			num_inactive_persistent;
-	zend_long			max_persistent;
+	unsigned short      		default_port;
 	bool				allow_persistent;
-	zend_ulong			default_port;
+	bool				allow_local_infile;
 	char				*default_host;
 	char				*default_user;
 	char				*default_pw;
 	char				*default_socket;
-	bool				allow_local_infile;
 	char				*local_infile_directory;
-	zend_long			error_no;
 	char				*error_msg;
+	zend_long			num_links;
+	zend_long			max_links;
+	zend_long 			num_active_persistent;
+	zend_long 			num_inactive_persistent;
+	zend_long			max_persistent;
+	zend_long			error_no;
 	zend_long			report_mode;
 	bool 				rollback_on_cached_plink;
 ZEND_END_MODULE_GLOBALS(mysqli)
diff --git a/ext/mysqli/tests/mysqli_default_port_error.phpt b/ext/mysqli/tests/mysqli_default_port_error.phpt
new file mode 100644
index 0000000000000..7d3658417c96c
--- /dev/null
+++ b/ext/mysqli/tests/mysqli_default_port_error.phpt
@@ -0,0 +1,21 @@
+--TEST--
+default_port ini setting
+--EXTENSIONS--
+mysqli
+--FILE--
+<?php
+	$orig_port = ini_get("mysqli.default_port");
+    ini_set('mysqli.default_port', 65536);
+	$new_port = ini_get("mysqli.default_port");
+	var_dump($orig_port === $new_port);
+    ini_set('mysqli.default_port', -1);
+	$new_port = ini_get("mysqli.default_port");
+	var_dump($orig_port === $new_port);
+    ini_set('mysqli.default_port', $orig_port - 1);
+	$new_port = ini_get("mysqli.default_port");
+	var_dump($orig_port === $new_port);
+?>
+--EXPECT--
+bool(true)
+bool(true)
+bool(false)