diff --git a/code/__HELPERS/mobs.dm b/code/__HELPERS/mobs.dm
index ff127fd3a48..8f0fa4f5131 100644
--- a/code/__HELPERS/mobs.dm
+++ b/code/__HELPERS/mobs.dm
@@ -316,7 +316,7 @@ This is always put in the attack log.
 
 	msg_admin_attack("[key_name_admin(user)] vs [key_name_admin(target)]: [what_done]", loglevel)
 
-/proc/do_mob(var/mob/user, var/mob/target, var/time = 30, var/uninterruptible = 0, progress = 1, datum/callback/extra_checks = null)
+/proc/do_mob(mob/user, mob/target, time = 30, uninterruptible = 0, progress = 1, list/extra_checks = list())
 	if(!user || !target)
 		return 0
 	var/user_loc = user.loc
@@ -349,7 +349,7 @@ This is always put in the attack log.
 			drifting = 0
 			user_loc = user.loc
 
-		if((!drifting && user.loc != user_loc) || target.loc != target_loc || user.get_active_hand() != holding || user.incapacitated() || user.lying || (extra_checks && !extra_checks.Invoke()))
+		if((!drifting && user.loc != user_loc) || target.loc != target_loc || user.get_active_hand() != holding || user.incapacitated() || user.lying || check_for_true_callbacks(extra_checks))
 			. = 0
 			break
 	if(progress)
diff --git a/code/game/objects/items/tools/tool_behaviour.dm b/code/game/objects/items/tools/tool_behaviour.dm
index 20d68038bff..986e3a981b2 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 = tool_check))
+			if(!do_mob(user, target, delay, extra_checks = list(tool_check)))
 				return
 
 		else