diff --git a/install/index.php b/install/index.php
index ca739c9606ec..79010fffb1af 100644
--- a/install/index.php
+++ b/install/index.php
@@ -549,6 +549,32 @@ public function checkdatabase($databaseConfig, $dbName) {
     }
   }
 
+  /**
+   * Connect via mysqli.
+   *
+   * This is exactly the same as mysqli_connect(), except that it accepts
+   * the port as part of the `$host`.
+   *
+   * @param string $host
+   *   Ex: 'localhost', 'localhost:3307', '127.0.0.1:3307', '[::1]', '[::1]:3307'.
+   * @param string $username
+   * @param string $password
+   * @param string $database
+   * @return \mysqli
+   */
+  protected function connect($host, $username, $password, $database = '') {
+    $hostParts = explode(':', $host);
+    if (count($hostParts) > 1 && strrpos($host, ']') !== strlen($host) - 1) {
+      $port = array_pop($hostParts);
+      $host = implode(':', $hostParts);
+    }
+    else {
+      $port = '';
+    }
+    $conn = @mysqli_connect($host, $username, $password, $database, $port);
+    return $conn;
+  }
+
   /**
    * Check everything except the database.
    */
@@ -949,7 +975,7 @@ public function requireApacheModule($moduleName, $testDetails) {
    */
   public function requireMysqlConnection($server, $username, $password, $testDetails) {
     $this->testing($testDetails);
-    $this->conn = @mysqli_connect($server, $username, $password);
+    $this->conn = $this->connect($server, $username, $password);
 
     if ($this->conn) {
       return TRUE;
@@ -966,7 +992,7 @@ public function requireMysqlConnection($server, $username, $password, $testDetai
    */
   public function requireMySQLServer($server, $testDetails) {
     $this->testing($testDetails);
-    $conn = @mysqli_connect($server, NULL, NULL);
+    $conn = $this->connect($server, NULL, NULL);
 
     if ($conn || mysqli_connect_errno() < 2000) {
       return TRUE;
@@ -1011,7 +1037,7 @@ public function requireMySQLVersion($version, $testDetails) {
    */
   public function requireMySQLInnoDB($server, $username, $password, $database, $testDetails) {
     $this->testing($testDetails);
-    $conn = @mysqli_connect($server, $username, $password);
+    $conn = $this->connect($server, $username, $password);
     if (!$conn) {
       $testDetails[2] .= ' ' . ts("Could not determine if MySQL has InnoDB support. Assuming no.");
       $this->error($testDetails);
@@ -1046,7 +1072,7 @@ public function requireMySQLInnoDB($server, $username, $password, $database, $te
    */
   public function requireMySQLTempTables($server, $username, $password, $database, $testDetails) {
     $this->testing($testDetails);
-    $conn = @mysqli_connect($server, $username, $password);
+    $conn = $this->connect($server, $username, $password);
     if (!$conn) {
       $testDetails[2] = ts('Could not login to the database.');
       $this->error($testDetails);
@@ -1076,7 +1102,7 @@ public function requireMySQLTempTables($server, $username, $password, $database,
    */
   public function requireMySQLTrigger($server, $username, $password, $database, $testDetails) {
     $this->testing($testDetails);
-    $conn = @mysqli_connect($server, $username, $password);
+    $conn = $this->connect($server, $username, $password);
     if (!$conn) {
       $testDetails[2] = ts('Could not login to the database.');
       $this->error($testDetails);
@@ -1116,7 +1142,7 @@ public function requireMySQLTrigger($server, $username, $password, $database, $t
    */
   public function requireMySQLLockTables($server, $username, $password, $database, $testDetails) {
     $this->testing($testDetails);
-    $conn = @mysqli_connect($server, $username, $password);
+    $conn = $this->connect($server, $username, $password);
     if (!$conn) {
       $testDetails[2] = ts('Could not connect to the database server.');
       $this->error($testDetails);
@@ -1163,7 +1189,7 @@ public function requireMySQLLockTables($server, $username, $password, $database,
    */
   public function requireMySQLAutoIncrementIncrementOne($server, $username, $password, $testDetails) {
     $this->testing($testDetails);
-    $conn = @mysqli_connect($server, $username, $password);
+    $conn = $this->connect($server, $username, $password);
     if (!$conn) {
       $testDetails[2] = ts('Could not connect to the database server.');
       $this->error($testDetails);
@@ -1197,7 +1223,7 @@ public function requireMySQLAutoIncrementIncrementOne($server, $username, $passw
    */
   public function requireMySQLThreadStack($server, $username, $password, $database, $minValueKB, $testDetails) {
     $this->testing($testDetails);
-    $conn = @mysqli_connect($server, $username, $password);
+    $conn = $this->connect($server, $username, $password);
     if (!$conn) {
       $testDetails[2] = ts('Could not connect to the database server.');
       $this->error($testDetails);
@@ -1241,7 +1267,7 @@ public function requireDatabaseOrCreatePermissions(
     $onlyRequire = FALSE
   ) {
     $this->testing($testDetails);
-    $conn = @mysqli_connect($server, $username, $password);
+    $conn = $this->connect($server, $username, $password);
 
     $okay = NULL;
     if (@mysqli_select_db($conn, $database)) {
@@ -1380,7 +1406,7 @@ class Installer extends InstallRequirements {
    * @param $database
    */
   public function createDatabaseIfNotExists($server, $username, $password, $database) {
-    $conn = @mysqli_connect($server, $username, $password);
+    $conn = $this->connect($server, $username, $password);
 
     if (@mysqli_select_db($conn, $database)) {
       // skip if database already present