diff --git a/code/__HELPERS/510.dm b/code/__HELPERS/510.dm
index 6bca2a51721..48e14bf14df 100644
--- a/code/__HELPERS/510.dm
+++ b/code/__HELPERS/510.dm
@@ -1,4 +1,8 @@
 // Helpers for running 510 code on older versions of BYOND.
+//	list of places with #if DM_VERSION defines for when we remove 509 support:
+//		master controller and subsystems.dm
+//		map loader (reader.dm)
+//		defines/tick.dm
 #if DM_VERSION < 510
 #define BYGEX "code/__HELPERS/bygex"
 /proc/replacetext(text, replace, replacement)
diff --git a/code/modules/admin/verbs/SDQL2/SDQL_2.dm b/code/modules/admin/verbs/SDQL2/SDQL_2.dm
index 5ab2eb7e142..e36a81bf833 100644
--- a/code/modules/admin/verbs/SDQL2/SDQL_2.dm
+++ b/code/modules/admin/verbs/SDQL2/SDQL_2.dm
@@ -75,6 +75,7 @@
 			if(char == "/" || char == "*")
 				for(var/from in from_objs)
 					objs += SDQL_get_all(type, from)
+					CHECK_TICK
 
 			else if(char == "'" || char == "\"")
 				objs += locate(copytext(type, 2, length(type)))
@@ -85,6 +86,7 @@
 			for(var/datum/d in objs_temp)
 				if(SDQL_expression(d, query_tree["where"]))
 					objs += d
+				CHECK_TICK
 
 		switch(query_tree[1])
 			if("call")
@@ -94,10 +96,12 @@
 				for(var/datum/d in objs)
 					for(var/v in call_list)
 						SDQL_callproc(d, v, args_list)
+						CHECK_TICK
 
 			if("delete")
 				for(var/datum/d in objs)
 					qdel(d)
+					CHECK_TICK
 
 			if("select")
 				var/text = ""
@@ -140,6 +144,7 @@
 						else
 							for(var/v in vals)
 								d.vars[v] = vals[v]
+						CHECK_TICK
 
 
 
@@ -246,31 +251,37 @@
 		for(var/mob/d in location)
 			if(istype(d, type))
 				out += d
+			CHECK_TICK
 
 	else if(ispath(type, /turf))
 		for(var/turf/d in location)
 			if(istype(d, type))
 				out += d
+			CHECK_TICK
 
 	else if(ispath(type, /obj))
 		for(var/obj/d in location)
 			if(istype(d, type))
 				out += d
+			CHECK_TICK
 
 	else if(ispath(type, /area))
 		for(var/area/d in location)
 			if(istype(d, type))
 				out += d
+			CHECK_TICK
 
 	else if(ispath(type, /atom))
 		for(var/atom/d in location)
 			if(istype(d, type))
 				out += d
+			CHECK_TICK
 
 	else
 		for(var/datum/d in location)
 			if(istype(d, type))
 				out += d
+			CHECK_TICK
 
 	return out
 
diff --git a/code/modules/admin/verbs/debug.dm b/code/modules/admin/verbs/debug.dm
index 90b385a3376..30074a1ed3f 100644
--- a/code/modules/admin/verbs/debug.dm
+++ b/code/modules/admin/verbs/debug.dm
@@ -406,6 +406,7 @@ var/global/list/g_fancy_list_of_types = null
 			if(istype(O, hsbitem))
 				counter++
 				qdel(O)
+			CHECK_TICK
 		log_admin("[key_name(src)] has deleted all ([counter]) instances of [hsbitem].")
 		message_admins("[key_name_admin(src)] has deleted all ([counter]) instances of [hsbitem].", 0)
 		feedback_add_details("admin_verb","DELA") //If you are copy-pasting this, ensure the 2nd parameter is unique to the new proc!
diff --git a/code/modules/admin/verbs/massmodvar.dm b/code/modules/admin/verbs/massmodvar.dm
index 5c65e22ebd4..c258e48c61a 100644
--- a/code/modules/admin/verbs/massmodvar.dm
+++ b/code/modules/admin/verbs/massmodvar.dm
@@ -145,32 +145,38 @@
 					for(var/mob/M in mob_list)
 						if ( istype(M , O.type) )
 							M.vars[variable] = O.vars[variable]
+						CHECK_TICK
 
 				else if(istype(O, /obj))
 					for(var/obj/A in world)
 						if ( istype(A , O.type) )
 							A.vars[variable] = O.vars[variable]
+						CHECK_TICK
 
 				else if(istype(O, /turf))
 					for(var/turf/A in world)
 						if ( istype(A , O.type) )
 							A.vars[variable] = O.vars[variable]
+						CHECK_TICK
 
 			else
 				if(istype(O, /mob))
 					for(var/mob/M in mob_list)
 						if (M.type == O.type)
 							M.vars[variable] = O.vars[variable]
+						CHECK_TICK
 
 				else if(istype(O, /obj))
 					for(var/obj/A in world)
 						if (A.type == O.type)
 							A.vars[variable] = O.vars[variable]
+						CHECK_TICK
 
 				else if(istype(O, /turf))
 					for(var/turf/A in world)
 						if (A.type == O.type)
 							A.vars[variable] = O.vars[variable]
+						CHECK_TICK
 
 		if("edit referenced object")
 			return .(O.vars[variable])
@@ -219,6 +225,7 @@
 									new_value = O.vars[variable] //We already processed the non-unique form for O, reuse it
 
 							M.vars[variable] = new_value
+						CHECK_TICK
 
 				else if(istype(O, /obj))
 					for(var/obj/A in world)
@@ -233,6 +240,7 @@
 									new_value = O.vars[variable]
 
 							A.vars[variable] = new_value
+						CHECK_TICK
 
 				else if(istype(O, /turf))
 					for(var/turf/A in world)
@@ -247,6 +255,7 @@
 									new_value = O.vars[variable]
 
 							A.vars[variable] = new_value
+						CHECK_TICK
 			else
 				if(istype(O, /mob))
 					for(var/mob/M in mob_list)
@@ -261,6 +270,7 @@
 									new_value = O.vars[variable]
 
 							M.vars[variable] = new_value
+						CHECK_TICK
 
 				else if(istype(O, /obj))
 					for(var/obj/A in world)
@@ -275,6 +285,7 @@
 									new_value = O.vars[variable]
 
 							A.vars[variable] = new_value
+						CHECK_TICK
 
 				else if(istype(O, /turf))
 					for(var/turf/A in world)
@@ -289,6 +300,7 @@
 									new_value = O.vars[variable]
 
 							A.vars[variable] = new_value
+						CHECK_TICK
 
 		if("num")
 			var/new_value = input("Enter new number:","Num",\
@@ -308,6 +320,7 @@
 								M.SetLuminosity(new_value)
 							else
 								M.vars[variable] = O.vars[variable]
+						CHECK_TICK
 
 				else if(istype(O, /obj))
 					for(var/obj/A in world)
@@ -316,6 +329,7 @@
 								A.SetLuminosity(new_value)
 							else
 								A.vars[variable] = O.vars[variable]
+						CHECK_TICK
 
 				else if(istype(O, /turf))
 					for(var/turf/A in world)
@@ -324,6 +338,7 @@
 								A.SetLuminosity(new_value)
 							else
 								A.vars[variable] = O.vars[variable]
+						CHECK_TICK
 
 			else
 				if(istype(O, /mob))
@@ -333,6 +348,7 @@
 								M.SetLuminosity(new_value)
 							else
 								M.vars[variable] = O.vars[variable]
+						CHECK_TICK
 
 				else if(istype(O, /obj))
 					for(var/obj/A in world)
@@ -341,6 +357,7 @@
 								A.SetLuminosity(new_value)
 							else
 								A.vars[variable] = O.vars[variable]
+						CHECK_TICK
 
 				else if(istype(O, /turf))
 					for(var/turf/A in world)
@@ -349,6 +366,7 @@
 								A.SetLuminosity(new_value)
 							else
 								A.vars[variable] = O.vars[variable]
+						CHECK_TICK
 
 		if("type")
 			var/new_value
@@ -360,31 +378,38 @@
 					for(var/mob/M in mob_list)
 						if ( istype(M , O.type) )
 							M.vars[variable] = O.vars[variable]
+						CHECK_TICK
 
 				else if(istype(O, /obj))
 					for(var/obj/A in world)
 						if ( istype(A , O.type) )
 							A.vars[variable] = O.vars[variable]
+						CHECK_TICK
 
 				else if(istype(O, /turf))
 					for(var/turf/A in world)
 						if ( istype(A , O.type) )
 							A.vars[variable] = O.vars[variable]
+						CHECK_TICK
+
 			else
 				if(istype(O, /mob))
 					for(var/mob/M in mob_list)
 						if (M.type == O.type)
 							M.vars[variable] = O.vars[variable]
+						CHECK_TICK
 
 				else if(istype(O, /obj))
 					for(var/obj/A in world)
 						if (A.type == O.type)
 							A.vars[variable] = O.vars[variable]
+						CHECK_TICK
 
 				else if(istype(O, /turf))
 					for(var/turf/A in world)
 						if (A.type == O.type)
 							A.vars[variable] = O.vars[variable]
+						CHECK_TICK
 
 		if("file")
 			var/new_value = input("Pick file:","File",O.vars[variable]) as null|file
@@ -396,31 +421,37 @@
 					for(var/mob/M in mob_list)
 						if ( istype(M , O.type) )
 							M.vars[variable] = O.vars[variable]
+						CHECK_TICK
 
 				else if(istype(O.type, /obj))
 					for(var/obj/A in world)
 						if ( istype(A , O.type) )
 							A.vars[variable] = O.vars[variable]
+						CHECK_TICK
 
 				else if(istype(O.type, /turf))
 					for(var/turf/A in world)
 						if ( istype(A , O.type) )
 							A.vars[variable] = O.vars[variable]
+						CHECK_TICK
 			else
 				if(istype(O, /mob))
 					for(var/mob/M in mob_list)
 						if (M.type == O.type)
 							M.vars[variable] = O.vars[variable]
+						CHECK_TICK
 
 				else if(istype(O, /obj))
 					for(var/obj/A in world)
 						if (A.type == O.type)
 							A.vars[variable] = O.vars[variable]
+						CHECK_TICK
 
 				else if(istype(O, /turf))
 					for(var/turf/A in world)
 						if (A.type == O.type)
 							A.vars[variable] = O.vars[variable]
+						CHECK_TICK
 
 		if("icon")
 			var/new_value = input("Pick icon:","Icon",O.vars[variable]) as null|icon
@@ -431,64 +462,76 @@
 					for(var/mob/M in mob_list)
 						if ( istype(M , O.type) )
 							M.vars[variable] = O.vars[variable]
+						CHECK_TICK
 
 				else if(istype(O, /obj))
 					for(var/obj/A in world)
 						if ( istype(A , O.type) )
 							A.vars[variable] = O.vars[variable]
+						CHECK_TICK
 
 				else if(istype(O, /turf))
 					for(var/turf/A in world)
 						if ( istype(A , O.type) )
 							A.vars[variable] = O.vars[variable]
+						CHECK_TICK
 
 			else
 				if(istype(O, /mob))
 					for(var/mob/M in mob_list)
 						if (M.type == O.type)
 							M.vars[variable] = O.vars[variable]
+						CHECK_TICK
 
 				else if(istype(O, /obj))
 					for(var/obj/A in world)
 						if (A.type == O.type)
 							A.vars[variable] = O.vars[variable]
+						CHECK_TICK
 
 				else if(istype(O, /turf))
 					for(var/turf/A in world)
 						if (A.type == O.type)
 							A.vars[variable] = O.vars[variable]
+						CHECK_TICK
 
 	if(method)
 		if(istype(O,/mob))
 			for(var/mob/M in mob_list)
 				if(istype(M,O.type))
 					M.on_varedit(variable)
+				CHECK_TICK
 
 		else if(istype(O,/obj))
 			for(var/obj/A in world)
 				if(istype(A,O.type))
 					A.on_varedit(variable)
+				CHECK_TICK
 
 		else if(istype(O,/turf))
 			for(var/turf/A in block(locate(1,1,1),locate(world.maxx,world.maxy,world.maxz)))
 				if(istype(A,O.type))
 					A.on_varedit(variable)
+				CHECK_TICK
 
 	else
 		if(istype(O, /mob))
 			for(var/mob/M in mob_list)
 				if(M.type == O.type)
 					M.on_varedit(variable)
+				CHECK_TICK
 
 		else if(istype(O, /obj))
 			for(var/obj/A in world)
 				if(A.type == O.type)
 					A.on_varedit(variable)
+				CHECK_TICK
 
 		else if(istype(O, /turf))
 			for(var/turf/A in world)
 				if(A.type == O.type)
 					A.on_varedit(variable)
+				CHECK_TICK
 
 	world.log << "### MassVarEdit by [src]: [O.type] [variable]=[html_encode("[O.vars[variable]]")]"
 	log_admin("[key_name(src)] mass modified [original_name]'s [variable] to [O.vars[variable]]")
diff --git a/code/modules/awaymissions/maploader/reader.dm b/code/modules/awaymissions/maploader/reader.dm
index 732f7c36251..e785f3a32f1 100644
--- a/code/modules/awaymissions/maploader/reader.dm
+++ b/code/modules/awaymissions/maploader/reader.dm
@@ -94,13 +94,20 @@ var/global/dmm_suite/preloader/_preloader = new
 				break
 
 			ycrd--
-
+#if DM_VERSION < 510
 			sleep(-1)
+#else
+			CHECK_TICK
+#endif
 
 		//reached End Of File
 		if(findtext(tfile,quote+"}",zpos,0)+2==tfile_len)
 			break
+#if DM_VERSION < 510
 		sleep(-1)
+#else
+		CHECK_TICK
+#endif
 
 /**
  * Fill a given tile with its area/turf/objects/mobs
@@ -158,7 +165,11 @@ var/global/dmm_suite/preloader/_preloader = new
 		members_attributes.len++
 		members_attributes[index++] = fields
 
+#if DM_VERSION < 510
 		sleep(-1)
+#else
+		CHECK_TICK
+#endif
 	while(dpos != 0)
 
 
@@ -211,6 +222,7 @@ var/global/dmm_suite/preloader/_preloader = new
 	//finally instance all remainings objects/mobs
 	for(index in 1 to first_turf_index-1)
 		instance_atom(members[index],members_attributes[index],xcrd,ycrd,zcrd)
+		CHECK_TICK
 
 ////////////////
 //Helpers procs