diff --git a/turtos/startup.lua b/turtos/startup.lua
index 64046ab..16380c6 100644
--- a/turtos/startup.lua
+++ b/turtos/startup.lua
@@ -1,3 +1,8 @@
+if not turtle then
+    printError("not a turtle")
+    return
+end
+
 _G._TOS_VER = "N/A"
 local tos_ver_fp = io.open("/.tos-ver", "r")
 if tos_ver_fp then