diff --git a/.tgs.yml b/.tgs.yml
index 91d2401153..fb78890c55 100644
--- a/.tgs.yml
+++ b/.tgs.yml
@@ -3,7 +3,7 @@
 version: 1
 # The BYOND version to use (kept in sync with dependencies.sh by the "TGS Test Suite" CI job)
 # Must be interpreted as a string, keep quoted
-byond: "516.1669"
+byond: "516.1673"
 # Folders to create in "<instance_path>/Configuration/GameStaticFiles/"
 static_files:
   # Config directory should be static
diff --git a/code/__byond_version_compat.dm b/code/__byond_version_compat.dm
index 0af2af7f4a..1c10ec753f 100644
--- a/code/__byond_version_compat.dm
+++ b/code/__byond_version_compat.dm
@@ -8,11 +8,11 @@
 
 //Update this whenever you need to take advantage of more recent byond features
 #define MIN_COMPILER_VERSION 516
-#define MIN_COMPILER_BUILD 1664
+#define MIN_COMPILER_BUILD 1667
 #if (DM_VERSION < MIN_COMPILER_VERSION || DM_BUILD < MIN_COMPILER_BUILD) && !defined(SPACEMAN_DMM) && !defined(OPENDREAM)
 //Don't forget to update this part
 #error Your version of BYOND is too out-of-date to compile this project. Go to https://secure.byond.com/download and update.
-#error You need version 516.1664 or higher
+#error You need version 516.1667 or higher
 #endif
 
 // Keep savefile compatibilty at minimum supported level
diff --git a/code/__defines/__globals.dm b/code/__defines/__globals.dm
index d355da20bc..f634abbcd5 100644
--- a/code/__defines/__globals.dm
+++ b/code/__defines/__globals.dm
@@ -48,6 +48,18 @@
 /// Create a typed list global that is initialized as an empty list
 #define GLOBAL_LIST_EMPTY_TYPED(X, Typepath) GLOBAL_LIST_INIT_TYPED(X, Typepath, list())
 
+/// Create an alist global with an initializer expression
+#define GLOBAL_ALIST_INIT(X, InitValue) GLOBAL_RAW(/alist/##X); GLOBAL_MANAGED(X, InitValue)
+
+/// Create an alist global that is initialized as an empty list
+#define GLOBAL_ALIST_EMPTY(X) GLOBAL_ALIST_INIT(X, alist())
+
+/// Create a typed alist global with an initializer expression
+//#define GLOBAL_ALIST_INIT_TYPED(X, Typepath, InitValue) GLOBAL_RAW(/alist##Typepath/X); GLOBAL_MANAGED(X, InitValue) // Missing in spacemandmm
+
+/// Create a typed alist global that is initialized as an empty list
+//#define GLOBAL_ALIST_EMPTY_TYPED(X, Typepath) GLOBAL_ALIST_INIT_TYPED(X, Typepath, alist()) // Missing in spacemandmm
+
 /// Create a typed global with an initializer expression
 #define GLOBAL_DATUM_INIT(X, Typepath, InitValue) GLOBAL_RAW(Typepath/##X); GLOBAL_MANAGED(X, InitValue)
 
@@ -57,5 +69,8 @@
 /// Create a null global list
 #define GLOBAL_LIST(X) GLOBAL_RAW(/list/##X); GLOBAL_UNMANAGED(X)
 
+/// Create a null global alist
+#define GLOBAL_ALIST(X) GLOBAL_RAW(/alist/##X); GLOBAL_UNMANAGED(X)
+
 /// Create a typed null global
 #define GLOBAL_DATUM(X, Typepath) GLOBAL_RAW(Typepath/##X); GLOBAL_UNMANAGED(X)
diff --git a/code/_helpers/_lists.dm b/code/_helpers/_lists.dm
index 8fe7dbf9c8..3e92c6ff18 100644
--- a/code/_helpers/_lists.dm
+++ b/code/_helpers/_lists.dm
@@ -1060,3 +1060,26 @@ GLOBAL_LIST_EMPTY(json_cache)
 			else if(value_1 != value_2)
 				return FALSE
 	return TRUE
+
+/**
+ * Attempts to convert a numeric keyed alist of (2=second, 1=first) to a list of (first, second).
+ *
+ * If you instead want to discard values and keep only keys, just do list + alist.
+ *
+ * Arguments:
+ * * to_flatten - The alist with sequential numeric keys to extract values from into a normal list.
+ * * assert - Whether to assert every key is numeric and in bounds.
+ */
+/proc/flatten_numeric_alist(alist/to_flatten, assert=TRUE)
+	RETURN_TYPE(/list)
+
+	var/count = length(to_flatten)
+	if(assert)
+		for(var/key in to_flatten)
+			if(!isnum(key) || key < 1 || key > count)
+				CRASH("flatten_numeric_alist not possible for alist: [json_encode(to_flatten)]")
+
+	var/list/retval = list()
+	for(var/i in 1 to count)
+		retval += to_flatten[i]
+	return retval
diff --git a/code/_helpers/global_lists.dm b/code/_helpers/global_lists.dm
index 79e259b88f..489a2dffb4 100644
--- a/code/_helpers/global_lists.dm
+++ b/code/_helpers/global_lists.dm
@@ -1214,7 +1214,7 @@ var/global/datum/emergency_shuttle_controller/emergency_shuttle = new
 
 GLOBAL_LIST_EMPTY(gun_choices)
 
-GLOBAL_LIST_INIT(severity_to_string, list(
+GLOBAL_ALIST_INIT(severity_to_string, alist(
 	EVENT_LEVEL_MUNDANE = "Mundane",
 	EVENT_LEVEL_MODERATE = "Moderate",
 	EVENT_LEVEL_MAJOR = "Major"
diff --git a/code/controllers/subsystems/events.dm b/code/controllers/subsystems/events.dm
index 25dcebb81f..f8261ed7f1 100644
--- a/code/controllers/subsystems/events.dm
+++ b/code/controllers/subsystems/events.dm
@@ -11,13 +11,13 @@ SUBSYSTEM_DEF(events)
 	var/list/datum/event/finished_events = list()
 
 	var/list/datum/event/allEvents
-	var/list/datum/event_container/event_containers
+	var/alist/event_containers
 
 	var/datum/event_meta/new_event = new
 
 /datum/controller/subsystem/events/Initialize()
 	allEvents = subtypesof(/datum/event)
-	event_containers = list(
+	event_containers = alist(
 			EVENT_LEVEL_MUNDANE 	= new/datum/event_container/mundane,
 			EVENT_LEVEL_MODERATE	= new/datum/event_container/moderate,
 			EVENT_LEVEL_MAJOR 		= new/datum/event_container/major
diff --git a/code/controllers/subsystems/timer.dm b/code/controllers/subsystems/timer.dm
index 6361b4d2c2..4640fc1119 100644
--- a/code/controllers/subsystems/timer.dm
+++ b/code/controllers/subsystems/timer.dm
@@ -379,7 +379,7 @@ SUBSYSTEM_DEF(timer)
 	var/spent = 0
 	/// Holds info about this timer, stored from the moment it was created
 	/// Used to create a visible "name" whenever the timer is stringified
-	var/list/timer_info
+	var/alist/timer_info
 	/// Next timed event in the bucket
 	var/datum/timedevent/next
 	/// Previous timed event in the bucket
@@ -521,7 +521,7 @@ SUBSYSTEM_DEF(timer)
 /datum/timedevent/proc/bucketJoin()
 #if defined(TIMER_DEBUG)
 	// Generate debug-friendly list for timer, more complex but also more expensive
-	timer_info = list(
+	timer_info = alist(
 		1 = id,
 		2 = timeToRun,
 		3 = wait,
@@ -536,7 +536,7 @@ SUBSYSTEM_DEF(timer)
 	)
 #else
 	// Generate a debuggable list for the timer, simpler but wayyyy cheaper, string generation (and ref/copy memes) is a bitch and this saves a LOT of time
-	timer_info = list(
+	timer_info = alist(
 		1 = id,
 		2 = timeToRun,
 		3 = wait,
diff --git a/code/modules/admin/verbs/atmosdebug.dm b/code/modules/admin/verbs/atmosdebug.dm
index 3cf0dab812..2eb8d5a3ca 100644
--- a/code/modules/admin/verbs/atmosdebug.dm
+++ b/code/modules/admin/verbs/atmosdebug.dm
@@ -7,38 +7,38 @@
 
 	feedback_add_details("admin_verb","CP") //If you are copy-pasting this, ensure the 2nd parameter is unique to the new proc!
 
-	if(tgui_alert(usr, "WARNING: This command should not be run on a live server. Do you want to continue?", "Check Piping", list("No", "Yes")) != "Yes")
+	if(tgui_alert(src, "WARNING: This command should not be run on a live server. Do you want to continue?", "Check Piping", list("No", "Yes")) != "Yes")
 		return
 
-	to_chat(usr, "Checking for disconnected pipes...")
+	to_chat(src, "Checking for disconnected pipes...")
 	//all plumbing - yes, some things might get stated twice, doesn't matter.
 	for (var/obj/machinery/atmospherics/plumbing in GLOB.machines)
 		if (plumbing.nodealert)
-			to_chat(usr, span_filter_adminlog(span_warning("Unconnected [plumbing.name] located at [plumbing.x],[plumbing.y],[plumbing.z] ([get_area(plumbing.loc)])")))
+			to_chat(src, span_filter_adminlog(span_warning("Unconnected [plumbing.name] located at [plumbing.x],[plumbing.y],[plumbing.z] ([get_area(plumbing.loc)])")))
 
 	//Manifolds
 	for (var/obj/machinery/atmospherics/pipe/manifold/pipe in GLOB.machines)
 		if (!pipe.node1 || !pipe.node2 || !pipe.node3)
-			to_chat(usr, span_filter_adminlog(span_warning("Unconnected [pipe.name] located at [pipe.x],[pipe.y],[pipe.z] ([get_area(pipe.loc)])")))
+			to_chat(src, span_filter_adminlog(span_warning("Unconnected [pipe.name] located at [pipe.x],[pipe.y],[pipe.z] ([get_area(pipe.loc)])")))
 
 	//Pipes
 	for (var/obj/machinery/atmospherics/pipe/simple/pipe in GLOB.machines)
 		if (!pipe.node1 || !pipe.node2)
-			to_chat(usr, span_filter_adminlog(span_warning("Unconnected [pipe.name] located at [pipe.x],[pipe.y],[pipe.z] ([get_area(pipe.loc)])")))
+			to_chat(src, span_filter_adminlog(span_warning("Unconnected [pipe.name] located at [pipe.x],[pipe.y],[pipe.z] ([get_area(pipe.loc)])")))
 
-	to_chat(usr, "Checking for overlapping pipes...")
+	to_chat(src, "Checking for overlapping pipes...")
 	next_turf:
 		for(var/turf/T in world)
 			for(var/dir in GLOB.cardinal)
-				var/list/connect_types = list(1 = 0, 2 = 0, 3 = 0)
+				var/alist/connect_types = alist(1 = 0, 2 = 0, 3 = 0)
 				for(var/obj/machinery/atmospherics/pipe in T)
 					if(dir & pipe.initialize_directions)
 						for(var/connect_type in pipe.connect_types)
 							connect_types[connect_type] += 1
 						if(connect_types[1] > 1 || connect_types[2] > 1 || connect_types[3] > 1)
-							to_chat(usr, span_filter_adminlog(span_warning("Overlapping pipe ([pipe.name]) located at [T.x],[T.y],[T.z] ([get_area(T)])")))
+							to_chat(src, span_filter_adminlog(span_warning("Overlapping pipe ([pipe.name]) located at [T.x],[T.y],[T.z] ([get_area(T)])")))
 							continue next_turf
-	to_chat(usr, "Done")
+	to_chat(src, "Done")
 
 /client/proc/powerdebug()
 	set category = "Mapping"
diff --git a/dependencies.sh b/dependencies.sh
index 73038e0985..9e68b1001f 100644
--- a/dependencies.sh
+++ b/dependencies.sh
@@ -5,7 +5,7 @@
 
 # byond version
 export BYOND_MAJOR=516
-export BYOND_MINOR=1669
+export BYOND_MINOR=1673
 
 # Macro Count
 export MACRO_COUNT=6