diff --git a/src/ConnectionConfig.php b/src/ConnectionConfig.php
index a4bcde4..cba4361 100644
--- a/src/ConnectionConfig.php
+++ b/src/ConnectionConfig.php
@@ -21,7 +21,7 @@ final class ConnectionConfig extends SqlConnectionConfig
 
         return new self(
             $parts["host"],
-            $parts["port"] ?? self::DEFAULT_PORT,
+            (int) ($parts["port"] ?? self::DEFAULT_PORT),
             $parts["user"] ?? null,
             $parts["password"] ?? null,
             $parts["db"] ?? null
diff --git a/src/TimeoutConnector.php b/src/TimeoutConnector.php
index 8aa98e1..d0adfe6 100644
--- a/src/TimeoutConnector.php
+++ b/src/TimeoutConnector.php
@@ -3,7 +3,7 @@
 namespace Amp\Postgres;
 
 use Amp\Promise;
-use Amp\Sql\ConnectionConfig;
+use Amp\Sql\ConnectionConfig as SqlConnectionConfig;
 use Amp\Sql\Connector;
 use Amp\Sql\FailureException;
 use Amp\TimeoutCancellationToken;
@@ -30,8 +30,12 @@ final class TimeoutConnector implements Connector
      *
      * @throws \Error If neither ext-pgsql or pecl-pq is loaded.
      */
-    public function connect(ConnectionConfig $connectionConfig): Promise
+    public function connect(SqlConnectionConfig $connectionConfig): Promise
     {
+        if (!$connectionConfig instanceof ConnectionConfig) {
+            throw new \TypeError(\sprintf("Must provide an instance of %s to Postgres connectors", ConnectionConfig::class));
+        }
+
         $token = new TimeoutCancellationToken($this->timeout);
 
         if (\extension_loaded("pq")) {