diff --git a/gamestate.lua b/gamestate.lua
index a73d319..c440180 100644
--- a/gamestate.lua
+++ b/gamestate.lua
@@ -36,6 +36,7 @@ function GS.new(t) return t or {} end -- constructor - deprecated!
 
 function GS.switch(to, ...)
 	assert(to, "Missing argument: Gamestate to switch to")
+	assert(to ~= GS, "Can't call switch with colon operator")
 	local pre = stack[#stack]
 	;(pre.leave or __NULL__)(pre)
 	;(to.init or __NULL__)(to)
@@ -46,6 +47,7 @@ end
 
 function GS.push(to, ...)
 	assert(to, "Missing argument: Gamestate to switch to")
+	assert(to ~= GS, "Can't call push with colon operator")
 	local pre = stack[#stack]
 	;(to.init or __NULL__)(to)
 	to.init = nil