diff --git a/core.lua b/core.lua
index db2652a..e01f5f7 100644
--- a/core.lua
+++ b/core.lua
@@ -1,5 +1,5 @@
 Aux = {
-    version = '2.9.18',
+    version = '2.9.19',
     blizzard_ui_shown = false,
 	orig = {},
 }
diff --git a/stack.lua b/stack.lua
index 505a9ab..7f3861d 100644
--- a/stack.lua
+++ b/stack.lua
@@ -112,7 +112,7 @@ function public.stop()
 		Aux.control.kill_thread(state.thread_id)
 
 		local callback, slot = state.callback, state.target_slot
-		if not private.matching_item(slot) then
+		if slot and not private.matching_item(slot) then
 			slot = nil
 		end