diff --git a/code/__byond_version_compat.dm b/code/__byond_version_compat.dm
index 186a8844bcf..0320e224c97 100644
--- a/code/__byond_version_compat.dm
+++ b/code/__byond_version_compat.dm
@@ -13,6 +13,9 @@
 #if (DM_VERSION == 516 && DM_BUILD == 1660)
 #error This version of BYOND (516.1660) has a bug which prevents this codebase from loading properly. If possible, update your BYOND version. Otherwise, visit www.byond.com/download/build to download an older release.
 #endif
+#if (DM_VERSION == 516 && (DM_BUILD == 1670 || DM_BUILD == 1671))
+#error This version of BYOND (516.1671) has a bug which prevents this codebase from compiling. If possible, update your BYOND version. Otherwise, visit www.byond.com/download/build to download an older release.
+#endif
 
 // Keep savefile compatibilty at minimum supported level
 /savefile/byond_version = MIN_COMPILER_VERSION
diff --git a/code/modules/client/client_procs.dm b/code/modules/client/client_procs.dm
index ccfe4ea99e0..4162a63a388 100644
--- a/code/modules/client/client_procs.dm
+++ b/code/modules/client/client_procs.dm
@@ -4,8 +4,11 @@
 
 GLOBAL_LIST_INIT(blacklisted_builds, list(
 	"1622" = "Bug breaking rendering can lead to wallhacks.",
-	))
-
+))
+GLOBAL_LIST_INIT(unrecommended_builds, list(
+	"1670" = "Bug breaking in-world text rendering.",
+	"1671" = "Bug breaking in-world text rendering.",
+))
 #define LIMITER_SIZE 5
 #define CURRENT_SECOND 1
 #define SECOND_COUNT 2
diff --git a/code/modules/mob/dead/new_player/login.dm b/code/modules/mob/dead/new_player/login.dm
index 0c41f717c06..5854c455346 100644
--- a/code/modules/mob/dead/new_player/login.dm
+++ b/code/modules/mob/dead/new_player/login.dm
@@ -56,4 +56,11 @@
 		var/tl = SSticker.GetTimeLeft()
 		to_chat(src, "Please set up your character and select \"Ready\". The game will start [tl > 0 ? "in about [DisplayTimeText(tl)]" : "soon"].")
 
+	if(GLOB.unrecommended_builds[num2text(client.byond_build)])
+		INVOKE_ASYNC(src, PROC_REF(unrcommended_build_alert))
 
+/mob/dead/new_player/proc/unrcommended_build_alert()
+	var/warning = "Hey! The build of byond you are running ([client.byond_build]) has one or more potential issues that may cause major gameplay disruptions.\n\n\
+		You may continue to play, but be aware you may encounter the following issue while playing:\n\"[GLOB.unrecommended_builds[num2text(client.byond_build)]]\"\n\n\
+		If possible, we recommend updating your BYOND version.\nIf you are on the latest version, download an earlier release instead from www.byond.com/download/build."
+	alert(src, warning, "Bad BYOND Build", "OK")