diff --git a/dist/index.js b/dist/index.js
index e50e40c..35729b4 100644
--- a/dist/index.js
+++ b/dist/index.js
@@ -8851,7 +8851,9 @@ class HttpClient {
                 maxSockets: maxSockets,
                 keepAlive: this._keepAlive,
                 proxy: {
-                    proxyAuth: `${proxyUrl.username}:${proxyUrl.password}`,
+                    ...((proxyUrl.username || proxyUrl.password) && {
+                        proxyAuth: `${proxyUrl.username}:${proxyUrl.password}`
+                    }),
                     host: proxyUrl.hostname,
                     port: proxyUrl.port
                 }