diff --git a/build.gradle b/build.gradle
index c467367d83..912210f52c 100644
--- a/build.gradle
+++ b/build.gradle
@@ -20,7 +20,7 @@ plugins {
 	id 'net.fabricmc.filament'
 }
 
-def minecraft_version = "1.20.5-pre3"
+def minecraft_version = "1.20.5-pre4"
 
 filament {
 	minecraftVersion = minecraft_version
diff --git a/mappings/net/minecraft/datafixer/fix/EntityMinecartIdentifiersFix.mapping b/mappings/net/minecraft/datafixer/fix/EntityMinecartIdentifiersFix.mapping
index 3723614032..981698e68d 100644
--- a/mappings/net/minecraft/datafixer/fix/EntityMinecartIdentifiersFix.mapping
+++ b/mappings/net/minecraft/datafixer/fix/EntityMinecartIdentifiersFix.mapping
@@ -1,2 +1 @@
 CLASS net/minecraft/class_3605 net/minecraft/datafixer/fix/EntityMinecartIdentifiersFix
-	FIELD field_15896 MINECARTS Ljava/util/List;
diff --git a/mappings/net/minecraft/world/biome/OverworldBiomeCreator.mapping b/mappings/net/minecraft/world/biome/OverworldBiomeCreator.mapping
index cad1cec437..a44fbee070 100644
--- a/mappings/net/minecraft/world/biome/OverworldBiomeCreator.mapping
+++ b/mappings/net/minecraft/world/biome/OverworldBiomeCreator.mapping
@@ -82,7 +82,7 @@ CLASS net/minecraft/class_5478 net/minecraft/world/biome/OverworldBiomeCreator
 		ARG 0 featureLookup
 		ARG 1 carverLookup
 		ARG 2 deep
-	METHOD method_30708 createSwamp (Lnet/minecraft/class_7871;Lnet/minecraft/class_7871;)Lnet/minecraft/class_1959;
+	METHOD method_30708 createSwamp (Lnet/minecraft/class_7871;Lnet/minecraft/class_7871;Ljava/util/function/Consumer;)Lnet/minecraft/class_1959;
 		ARG 0 featureLookup
 		ARG 1 carverLookup
 	METHOD method_30709 createLukewarmOcean (Lnet/minecraft/class_7871;Lnet/minecraft/class_7871;Z)Lnet/minecraft/class_1959;
@@ -155,6 +155,6 @@ CLASS net/minecraft/class_5478 net/minecraft/world/biome/OverworldBiomeCreator
 	METHOD method_42061 createDeepDark (Lnet/minecraft/class_7871;Lnet/minecraft/class_7871;)Lnet/minecraft/class_1959;
 		ARG 0 featureLookup
 		ARG 1 carverLookup
-	METHOD method_43232 createMangroveSwamp (Lnet/minecraft/class_7871;Lnet/minecraft/class_7871;)Lnet/minecraft/class_1959;
+	METHOD method_43232 createMangroveSwamp (Lnet/minecraft/class_7871;Lnet/minecraft/class_7871;Ljava/util/function/Consumer;)Lnet/minecraft/class_1959;
 		ARG 0 featureLookup
 		ARG 1 carverLookup