diff --git a/packages/core/src/plugin/figma.ts b/packages/core/src/plugin/figma.ts
index 28db26a7a9..0d8d966ee3 100644
--- a/packages/core/src/plugin/figma.ts
+++ b/packages/core/src/plugin/figma.ts
@@ -7,16 +7,16 @@ import { ConfigMCP } from "../config/mcp"
 import { MCP } from "../mcp/index"
 
 const CLIENT_ID = "3zVHNs9kINDDrk8loekLZV"
+const CALLBACK_PORT = 19876
 
 export function apply(server: typeof ConfigMCP.Server.Type) {
   if (server.type !== "remote" || server.oauth === false) return server
   if (!URL.canParse(server.url) || new URL(server.url).hostname !== "mcp.figma.com") return server
-  if (server.oauth?.client_id) return server
   if (server.oauth) {
-    Object.assign(server.oauth, { client_id: CLIENT_ID })
+    Object.assign(server.oauth, { client_id: server.oauth.client_id ?? CLIENT_ID, callback_port: CALLBACK_PORT })
     return server
   }
-  Object.assign(server, { oauth: { client_id: CLIENT_ID } })
+  Object.assign(server, { oauth: { client_id: CLIENT_ID, callback_port: CALLBACK_PORT } })
   return server
 }
 
diff --git a/packages/core/test/plugin/figma.test.ts b/packages/core/test/plugin/figma.test.ts
index 794a31e988..f150941985 100644
--- a/packages/core/test/plugin/figma.test.ts
+++ b/packages/core/test/plugin/figma.test.ts
@@ -12,19 +12,23 @@ describe("plugin.figma", () => {
 
     FigmaPlugin.apply(server)
 
-    expect(server.oauth).toEqual({ client_id: "3zVHNs9kINDDrk8loekLZV", scope: "mcp:connect" })
+    expect(server.oauth).toEqual({
+      client_id: "3zVHNs9kINDDrk8loekLZV",
+      callback_port: 19876,
+      scope: "mcp:connect",
+    })
   })
 
   test("preserves an existing client ID", () => {
     const server = new ConfigMCP.Remote({
       type: "remote",
       url: "https://mcp.figma.com/mcp",
-      oauth: new ConfigMCP.OAuth({ client_id: "configured-client-id" }),
+      oauth: new ConfigMCP.OAuth({ client_id: "configured-client-id", callback_port: 4321 }),
     })
 
     FigmaPlugin.apply(server)
 
-    expect(server.oauth).toEqual({ client_id: "configured-client-id" })
+    expect(server.oauth).toEqual({ client_id: "configured-client-id", callback_port: 19876 })
   })
 
   test("does not enable OAuth or modify non-Figma servers", () => {