diff --git a/src/http.ts b/src/http.ts
index b04caf9c4..995d2f83e 100644
--- a/src/http.ts
+++ b/src/http.ts
@@ -23,11 +23,42 @@ export interface IAttachment {
   body: NodeJS.ReadableStream;
 }
 
-function getPortFromUrl(url: URL): string {
-  if (url.port) return url.port;
-  if (url.protocol.toLowerCase() === 'https:') return '443';
-  if (url.protocol.toLowerCase() === 'http:') return '80';
-  return '';
+// The URL API normalizes away default ports (:80 on http, :443 on https),
+// so parse the port from the raw URL string to preserve ports.
+function getPortFromUrl(url: string): string {
+  // Capture the authority section (everything between :// and the first /?#)
+  const authorityMatch = /^[a-z][a-z0-9+.-]*:\/\/([^/?#]+)/i.exec(url);
+  if (!authorityMatch) {
+    return '';
+  }
+
+  const hostPort = authorityMatch[1];
+
+  // IPv6 address: [::1] or [::1]:port
+  if (hostPort.startsWith('[')) {
+    const bracketEnd = hostPort.indexOf(']');
+    if (bracketEnd !== -1 && hostPort[bracketEnd + 1] === ':') {
+      const port = hostPort.slice(bracketEnd + 2);
+      return /^\d+$/.test(port) ? port : '';
+    }
+    return '';
+  }
+
+  // IPv4 / hostname: host or host:port
+  const colonIndex = hostPort.lastIndexOf(':');
+  if (colonIndex === -1) {
+    return '';
+  }
+  const port = hostPort.slice(colonIndex + 1);
+  return /^\d+$/.test(port) ? port : '';
+}
+
+// Add brackets to IPv6 addresses
+function bracketIPv6(hostname: string): string {
+  if (hostname.startsWith('[') || hostname.indexOf(':') === -1) {
+    return hostname;
+  }
+  return `[${hostname}]`;
 }
 
 /**
@@ -59,16 +90,15 @@ export class HttpClient implements IHttpClient {
     const curl = new URL(rurl);
     const method = data ? 'POST' : 'GET';
 
-    const host = curl.hostname;
-
-    const port = getPortFromUrl(curl);
+    const port = getPortFromUrl(rurl);
+    const host = port ? `${bracketIPv6(curl.hostname)}:${port}` : curl.host || curl.hostname;
     const headers: IHeaders = {
       'User-Agent': 'node-soap/' + version,
       'Accept': 'text/html,application/xhtml+xml,application/xml,text/xml;q=0.9,*/*;q=0.8',
       'Accept-Encoding': 'none',
       'Accept-Charset': 'utf-8',
       ...(exoptions.forever && { Connection: 'keep-alive' }),
-      'Host': host + (port ? ':' + port : ''),
+      'Host': host,
     };
     const mergeOptions = ['headers'];
 
diff --git a/test/client-customHttp-test.js b/test/client-customHttp-test.js
index 09a88aeeb..c56e88b8b 100644
--- a/test/client-customHttp-test.js
+++ b/test/client-customHttp-test.js
@@ -116,3 +116,16 @@ it('should allow customization of httpClient and the wsdl file download should p
     done();
   });
 });
+
+it('should not append default ports to Host header', function () {
+  var client = new httpClient();
+
+  var httpsReq = client.buildRequest('https://example.com/service?wsdl', null);
+  assert.equal(httpsReq.headers.Host, 'example.com');
+
+  var httpReq = client.buildRequest('http://example.com/service?wsdl', null);
+  assert.equal(httpReq.headers.Host, 'example.com');
+
+  var explicitPortReq = client.buildRequest('https://example.com:8443/service?wsdl', null);
+  assert.equal(explicitPortReq.headers.Host, 'example.com:8443');
+});
diff --git a/tsconfig.json b/tsconfig.json
index e6de16066..30c6a58e5 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -9,7 +9,8 @@
     "sourceMap": true,
     "declaration": true,
     "stripInternal": true,
-    "skipLibCheck": true
+    "skipLibCheck": true,
+    "types": ["node"]
   },
   "include": ["src", "./eslint.config.mjs"],
   "exclude": ["node_modules"]