diff --git a/code/game/machinery/doors/airlock.dm b/code/game/machinery/doors/airlock.dm
index 692024899a2..bf83e6c5d49 100644
--- a/code/game/machinery/doors/airlock.dm
+++ b/code/game/machinery/doors/airlock.dm
@@ -1003,7 +1003,7 @@ About the new airlock wires panel:
 					"<span class='notice'>You begin [welded ? "unwelding":"welding"] the airlock...</span>", \
 					"<span class='italics'>You hear welding.</span>")
 
-				if(I.use_tool(src, user, 40, volume = I.tool_volume, extra_checks = list(CALLBACK(src, .proc/weld_checks, I, user))))
+				if(I.use_tool(src, user, 40, volume = I.tool_volume, extra_checks = CALLBACK(src, .proc/weld_checks, I, user)))
 					if(!density && !welded)
 						return
 					welded = !welded
@@ -1014,7 +1014,7 @@ About the new airlock wires panel:
 				user.visible_message("[user] is welding the airlock.", \
 					"<span class='notice'>You begin repairing the airlock...</span>", \
 					"<span class='italics'>You hear welding.</span>")
-				if(I.use_tool(src, user, 40, volume = I.tool_volume, extra_checks = list(CALLBACK(src, .proc/weld_checks, I, user))))
+				if(I.use_tool(src, user, 40, volume = I.tool_volume, extra_checks = CALLBACK(src, .proc/weld_checks, I, user)))
 					obj_integrity = max_integrity
 					stat &= ~BROKEN
 					user.visible_message("[user.name] has repaired [src].", \
diff --git a/code/game/objects/items/tools/tool_behaviour.dm b/code/game/objects/items/tools/tool_behaviour.dm
index 80b00dcd1ed..20d68038bff 100644
--- a/code/game/objects/items/tools/tool_behaviour.dm
+++ b/code/game/objects/items/tools/tool_behaviour.dm
@@ -16,7 +16,7 @@
 		var/datum/callback/tool_check = CALLBACK(src, .proc/tool_check_callback, user, target, amount, extra_checks)
 
 		if(ismob(target))
-			if(!do_mob(user, target, delay, extra_checks = list(tool_check)))
+			if(!do_mob(user, target, delay, extra_checks = tool_check))
 				return
 
 		else
@@ -57,4 +57,4 @@
 
 // Used in a callback that is passed by use_tool into do_after call. Do not override, do not call manually.
 /obj/item/proc/tool_check_callback(mob/living/user, atom/target, amount, datum/callback/extra_checks)
-	return tool_use_check(user, amount) && (!extra_checks || extra_checks.Invoke())
+	return tool_use_check(user, amount) && (extra_checks && !extra_checks.Invoke())
diff --git a/code/game/objects/structures/window.dm b/code/game/objects/structures/window.dm
index 8fe46ca052d..9faab45cf97 100644
--- a/code/game/objects/structures/window.dm
+++ b/code/game/objects/structures/window.dm
@@ -254,7 +254,7 @@ GLOBAL_LIST_INIT(wcCommon, pick(list("#379963", "#0d8395", "#58b5c3", "#49e46e",
 	if(!can_be_reached(user))
 		return
 	to_chat(user, "<span class='notice'>You begin to lever the window [state == WINDOW_OUT_OF_FRAME ? "into":"out of"] the frame...</span>")
-	if(!I.use_tool(src, user, decon_speed, volume = I.tool_volume, extra_checks = list(CALLBACK(src, .proc/check_state_and_anchored, state, anchored))))
+	if(!I.use_tool(src, user, decon_speed, volume = I.tool_volume, extra_checks = CALLBACK(src, .proc/check_state_and_anchored, state, anchored)))
 		return
 	state = (state == WINDOW_OUT_OF_FRAME ? WINDOW_IN_FRAME : WINDOW_OUT_OF_FRAME)
 	to_chat(user, "<span class='notice'>You pry the window [state == WINDOW_IN_FRAME ? "into":"out of"] the frame.</span>")
@@ -268,20 +268,20 @@ GLOBAL_LIST_INIT(wcCommon, pick(list("#379963", "#0d8395", "#58b5c3", "#49e46e",
 	if(reinf)
 		if(state == WINDOW_SCREWED_TO_FRAME || state == WINDOW_IN_FRAME)
 			to_chat(user, "<span class='notice'>You begin to [state == WINDOW_SCREWED_TO_FRAME ? "unscrew the window from":"screw the window to"] the frame...</span>")
-			if(!I.use_tool(src, user, decon_speed, volume = I.tool_volume, extra_checks = list(CALLBACK(src, .proc/check_state_and_anchored, state, anchored))))
+			if(!I.use_tool(src, user, decon_speed, volume = I.tool_volume, extra_checks = CALLBACK(src, .proc/check_state_and_anchored, state, anchored)))
 				return
 			state = (state == WINDOW_IN_FRAME ? WINDOW_SCREWED_TO_FRAME : WINDOW_IN_FRAME)
 			to_chat(user, "<span class='notice'>You [state == WINDOW_IN_FRAME ? "unfasten the window from":"fasten the window to"] the frame.</span>")
 		else if(state == WINDOW_OUT_OF_FRAME)
 			to_chat(user, "<span class='notice'>You begin to [anchored ? "unscrew the frame from":"screw the frame to"] the floor...</span>")
-			if(!I.use_tool(src, user, decon_speed, volume = I.tool_volume, extra_checks = list(CALLBACK(src, .proc/check_state_and_anchored, state, anchored))))
+			if(!I.use_tool(src, user, decon_speed, volume = I.tool_volume, extra_checks = CALLBACK(src, .proc/check_state_and_anchored, state, anchored)))
 				return
 			anchored = !anchored
 			update_nearby_icons()
 			to_chat(user, "<span class='notice'>You [anchored ? "fasten the frame to":"unfasten the frame from"] the floor.</span>")
 	else //if we're not reinforced, we don't need to check or update state
 		to_chat(user, "<span class='notice'>You begin to [anchored ? "unscrew the window from":"screw the window to"] the floor...</span>")
-		if(!I.use_tool(src, user, decon_speed, volume = I.tool_volume, extra_checks = list(CALLBACK(src, .proc/check_anchored, anchored))))
+		if(!I.use_tool(src, user, decon_speed, volume = I.tool_volume, extra_checks = CALLBACK(src, .proc/check_anchored, anchored)))
 			return
 		anchored = !anchored
 		air_update_turf(TRUE)
@@ -297,7 +297,7 @@ GLOBAL_LIST_INIT(wcCommon, pick(list("#379963", "#0d8395", "#58b5c3", "#49e46e",
 	if(!can_be_reached(user))
 		return
 	TOOL_ATTEMPT_DISMANTLE_MESSAGE
-	if(!I.use_tool(src, user, decon_speed, volume = I.tool_volume, extra_checks = list(CALLBACK(src, .proc/check_state_and_anchored, state, anchored))))
+	if(!I.use_tool(src, user, decon_speed, volume = I.tool_volume, extra_checks = CALLBACK(src, .proc/check_state_and_anchored, state, anchored)))
 		return
 	var/obj/item/stack/sheet/G = new glass_type(user.loc, glass_amount)
 	G.add_fingerprint(user)