diff --git a/link/serial.fnl b/link/serial.fnl
index c06a7c7..069973a 100644
--- a/link/serial.fnl
+++ b/link/serial.fnl
@@ -1,5 +1,5 @@
 ; using https://github.com/srdgame/librs232
-(local rs232 (require :luars232))
+(local (_ rs232) (pcall #(require :luars232)))
 (local command (require "core.command"))
 
 (fn check [err ...]
diff --git a/main.lua b/main.lua
index 739f789..e7b4c91 100644
--- a/main.lua
+++ b/main.lua
@@ -5,7 +5,7 @@ fv = fennel.view
 pp = function(x) print(fv(x)) end
 lume = require("lib.lume")
 -- these set global variables and can't be required after requiring core.strict
-luars232 = require("luars232")
+_, luars232 = pcall(function () require("luars232") end)
 
 _coroutine_resume = coroutine.resume
 function coroutine.resume(...)