diff --git a/code/_globalvars/lists/mobs.dm b/code/_globalvars/lists/mobs.dm
index 0c28353395d4..fb00d8bdf283 100644
--- a/code/_globalvars/lists/mobs.dm
+++ b/code/_globalvars/lists/mobs.dm
@@ -35,6 +35,8 @@ GLOBAL_LIST_EMPTY(aiEyes)
 ///underages who have been reported to security for trying to buy things they shouldn't, so they can't spam
 GLOBAL_LIST_EMPTY(narcd_underages)
 
+GLOBAL_LIST_EMPTY(real_names_joined)
+
 GLOBAL_LIST_EMPTY(language_datum_instances)
 GLOBAL_LIST_EMPTY(all_languages)
 
diff --git a/code/modules/mob/dead/new_player/new_player.dm b/code/modules/mob/dead/new_player/new_player.dm
index 6f37de4c4c77..d7865c9d2276 100644
--- a/code/modules/mob/dead/new_player/new_player.dm
+++ b/code/modules/mob/dead/new_player/new_player.dm
@@ -291,6 +291,12 @@
 	if(auth_check)
 		return
 
+	if(!client.prefs.randomise[RANDOM_NAME]) // do they have random names enabled
+		var/name = client.prefs.real_name
+		if(GLOB.real_names_joined.Find(name)) // is there someone who spawned with the same name
+			to_chat(usr, "<span class='warning'>Someone has spawned with this name already.")
+			return FALSE
+
 	var/error = IsJobUnavailable(job, ship, check_playtime)
 	if(error != JOB_AVAILABLE)
 		alert(src, get_job_unavailable_error_message(error, job))
@@ -398,6 +404,7 @@
 	close_spawn_windows()
 
 	var/mob/living/carbon/human/H = new(loc)
+	GLOB.joined_player_list += ckey
 
 	var/frn = CONFIG_GET(flag/force_random_names)
 	var/admin_anon_names = SSticker.anonymousnames
@@ -418,6 +425,7 @@
 		is_antag = TRUE
 
 	client.prefs.copy_to(H, antagonist = is_antag)
+	update_names_joined_list(H.real_name)
 	H.dna.update_dna_identity()
 	if(mind)
 		if(transfer_after)
diff --git a/code/modules/mob/mob.dm b/code/modules/mob/mob.dm
index 44aa701a466d..6e60af7ed244 100644
--- a/code/modules/mob/mob.dm
+++ b/code/modules/mob/mob.dm
@@ -1095,6 +1095,14 @@
 		return LAZYLEN(match_list)
 	return FALSE
 
+/mob/proc/update_joined_player_list(newname, oldname)
+	if(newname == oldname)
+		return
+	if(oldname)
+		GLOB.joined_player_list -= oldname
+	if(newname)
+		GLOB.joined_player_list[newname] = TRUE
+
 
 /**
  * Fully update the name of a mob
@@ -1110,6 +1118,9 @@
 
 	log_played_names(ckey,newname)
 
+	if(GLOB.joined_player_list[oldname])
+		update_joined_player_list(newname, oldname)
+
 	real_name = newname
 	name = newname
 	if(mind)
@@ -1195,6 +1206,11 @@
 	if(client.mouse_override_icon)
 		client.mouse_pointer_icon = client.mouse_override_icon
 
+/mob/proc/update_names_joined_list(new_name, old_name)
+	if(old_name)
+		GLOB.real_names_joined -= old_name
+	if(new_name)
+		GLOB.real_names_joined[new_name] = TRUE
 
 ///This mob is abile to read books
 /mob/proc/is_literate()