diff --git a/src/URLFixer.php b/src/URLFixer.php
index cd74c73..85a0b48 100644
--- a/src/URLFixer.php
+++ b/src/URLFixer.php
@@ -50,12 +50,15 @@ public function fixSiteURL(string $url): string
 	}
 
 	/**
-	 * Ensure that the network site URL contains the /wp subdirectory.
+	 * Ensure that the network site URL contains the /wp subdirectory and uses the current request host.
 	 */
 	public function fixNetworkSiteURL(string $url, string $path): string
 	{
 		$path = ltrim($path, '/');
-		$url = substr($url, 0, strlen($url) - strlen($path));
+
+		$scheme = is_ssl() ? 'https' : 'http';
+		$host = $_SERVER['HTTP_HOST'] ?? parse_url($url, PHP_URL_HOST);
+		$url = $scheme . '://' . $host . '/';
 
 		if (substr($url, -3) !== 'wp/') {
 			$url .= 'wp/';