diff --git a/src/main/resources/assets/opencomputers/loot/openos/boot/00_base.lua b/src/main/resources/assets/opencomputers/loot/openos/boot/00_base.lua
index 7bd7b3aba..475af463c 100644
--- a/src/main/resources/assets/opencomputers/loot/openos/boot/00_base.lua
+++ b/src/main/resources/assets/opencomputers/loot/openos/boot/00_base.lua
@@ -34,7 +34,7 @@ function print(...)
   local stdout = io.stdout
   local pre = ""
   for i = 1, args.n do
-    stdout:write(pre, tostring(args[i]))
+    stdout:write(pre, assert(tostring(args[i]), "'tostring' must return a string to 'print'"))
     pre = "\t"
   end
   stdout:write("\n")