diff --git a/technic/machines/register/cables.lua b/technic/machines/register/cables.lua
index 51d8b8e..95dcaea 100644
--- a/technic/machines/register/cables.lua
+++ b/technic/machines/register/cables.lua
@@ -12,6 +12,9 @@ function technic.get_cable_tier(name)
 end
 
 function technic.register_cable_tier(name, tier)
+	assert(technic.machines[tier], "Tier does not exist")
+	assert(type(name) == "string", "Invalid node name")
+
 	cable_tier[name] = tier
 end