diff --git a/cli/src/transport.ts b/cli/src/transport.ts
index e693f246..5df44f30 100644
--- a/cli/src/transport.ts
+++ b/cli/src/transport.ts
@@ -15,7 +15,11 @@ export type TransportOptions = {
 
 function createSSETransport(options: TransportOptions): Transport {
   const baseUrl = new URL(options.url ?? "");
+  // Create new URL while preserving the port from baseUrl
   const sseUrl = new URL("/sse", baseUrl);
+  if (baseUrl.port) {
+    sseUrl.port = baseUrl.port;
+  }
 
   return new SSEClientTransport(sseUrl);
 }
diff --git a/client/src/lib/hooks/useConnection.ts b/client/src/lib/hooks/useConnection.ts
index 27bc11a2..98ae0447 100644
--- a/client/src/lib/hooks/useConnection.ts
+++ b/client/src/lib/hooks/useConnection.ts
@@ -280,6 +280,8 @@ export function useConnection({
       return;
     }
     let mcpProxyServerUrl;
+    const originalUrl = new URL(sseUrl);
+    
     switch (transportType) {
       case "stdio":
         mcpProxyServerUrl = new URL(`${getMCPProxyAddress(config)}/stdio`);
@@ -290,12 +292,12 @@ export function useConnection({
 
       case "sse":
         mcpProxyServerUrl = new URL(`${getMCPProxyAddress(config)}/sse`);
-        mcpProxyServerUrl.searchParams.append("url", sseUrl);
+        mcpProxyServerUrl.searchParams.append("url", originalUrl.toString());
         break;
 
       case "streamable-http":
         mcpProxyServerUrl = new URL(`${getMCPProxyAddress(config)}/mcp`);
-        mcpProxyServerUrl.searchParams.append("url", sseUrl);
+        mcpProxyServerUrl.searchParams.append("url", originalUrl.toString());
         break;
     }
     (mcpProxyServerUrl as URL).searchParams.append(