diff --git a/lua/opencode/cli/process/init.lua b/lua/opencode/cli/process/init.lua
index 2743364..464e689 100644
--- a/lua/opencode/cli/process/init.lua
+++ b/lua/opencode/cli/process/init.lua
@@ -4,7 +4,7 @@ local M = {}
 ---Retrieval is platform-dependent.
 ---@class opencode.cli.process.Process
 ---@field pid number
----@field port number
+---@field port number?
 
 ---@return opencode.cli.process.Process[]
 function M.get()
diff --git a/lua/opencode/cli/server.lua b/lua/opencode/cli/server.lua
index aba7490..c6cc5a3 100644
--- a/lua/opencode/cli/server.lua
+++ b/lua/opencode/cli/server.lua
@@ -25,10 +25,13 @@ local M = {}
 
 ---Verify that an `opencode` process is responding on the given port,
 ---and fetch some details about it.
----@param port number
+---@param port number?
 ---@return Promise<opencode.cli.server.Server>
 local function get_server(port)
   local Promise = require("opencode.promise")
+  if not port then
+    return Promise.reject("This process is not listening on any port.")
+  end
   return Promise
     .new(function(resolve, reject)
       require("opencode.cli.client").get_path(port, function(path)