diff --git a/common/src/main/java/com/viaversion/viaversion/protocols/protocol1_20_5to1_20_3/data/MappingData.java b/common/src/main/java/com/viaversion/viaversion/protocols/protocol1_20_5to1_20_3/data/MappingData.java
index 2d5ac57af..2c5afc755 100644
--- a/common/src/main/java/com/viaversion/viaversion/protocols/protocol1_20_5to1_20_3/data/MappingData.java
+++ b/common/src/main/java/com/viaversion/viaversion/protocols/protocol1_20_5to1_20_3/data/MappingData.java
@@ -28,6 +28,7 @@ public class MappingData extends MappingDataBase {
 
     private KeyMappings items;
     private KeyMappings blocks;
+    private KeyMappings sounds;
 
     public MappingData() {
         super("1.20.3", "1.20.5");
@@ -37,9 +38,10 @@ public class MappingData extends MappingDataBase {
     protected void loadExtras(final CompoundTag data) {
         super.loadExtras(data);
 
-        final CompoundTag extraMappings = MappingDataLoader.INSTANCE.loadNBT("items-blocks-1.20.3.nbt");
+        final CompoundTag extraMappings = MappingDataLoader.INSTANCE.loadNBT("extra-identifiers-1.20.3.nbt");
         items = new KeyMappings(extraMappings.getListTag("items", StringTag.class));
         blocks = new KeyMappings(extraMappings.getListTag("blocks", StringTag.class));
+        sounds = new KeyMappings(extraMappings.getListTag("sounds", StringTag.class));
     }
 
     public int itemId(final String name) {
@@ -57,4 +59,12 @@ public class MappingData extends MappingDataBase {
     public @Nullable String blockName(final int id) {
         return blocks.idToKey(id);
     }
+
+    public int soundId(final String name) {
+        return sounds.keyToId(name);
+    }
+
+    public @Nullable String soundName(final int id) {
+        return sounds.idToKey(id);
+    }
 }
diff --git a/common/src/main/java/com/viaversion/viaversion/protocols/protocol1_20_5to1_20_3/rewriter/EntityPacketRewriter1_20_5.java b/common/src/main/java/com/viaversion/viaversion/protocols/protocol1_20_5to1_20_3/rewriter/EntityPacketRewriter1_20_5.java
index ec8758a06..e3000274a 100644
--- a/common/src/main/java/com/viaversion/viaversion/protocols/protocol1_20_5to1_20_3/rewriter/EntityPacketRewriter1_20_5.java
+++ b/common/src/main/java/com/viaversion/viaversion/protocols/protocol1_20_5to1_20_3/rewriter/EntityPacketRewriter1_20_5.java
@@ -42,6 +42,7 @@ import com.viaversion.viaversion.rewriter.EntityRewriter;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.UUID;
+import org.checkerframework.checker.nullness.qual.Nullable;
 
 public final class EntityPacketRewriter1_20_5 extends EntityRewriter<ClientboundPacket1_20_3, Protocol1_20_5To1_20_3> {
 
@@ -76,6 +77,16 @@ public final class EntityPacketRewriter1_20_5 extends EntityRewriter<Clientbound
                 }
             }
 
+            // Fixup sound ids that are now hard checked against the registry
+            final ListTag<CompoundTag> biomes = registryData.getCompoundTag("minecraft:worldgen/biome").getListTag("value", CompoundTag.class);
+            for (final CompoundTag biome : biomes) {
+                final CompoundTag effects = biome.getCompoundTag("element").getCompoundTag("effects");
+                checkSoundTag(effects.getCompoundTag("mood_sound"), "sound");
+                checkSoundTag(effects.getCompoundTag("additions_sound"), "sound");
+                checkSoundTag(effects.getCompoundTag("music"), "sound");
+                checkSoundTag(effects, "ambient_sound");
+            }
+
             for (final Map.Entry<String, Tag> entry : registryData.entrySet()) {
                 final CompoundTag entryTag = (CompoundTag) entry.getValue();
                 final String type = entryTag.getString("type");
@@ -211,6 +222,20 @@ public final class EntityPacketRewriter1_20_5 extends EntityRewriter<Clientbound
         });
     }
 
+    private void checkSoundTag(@Nullable final CompoundTag tag, final String key) {
+        if (tag == null) {
+            return;
+        }
+
+        final String sound = tag.getString(key);
+        if (sound != null && protocol.getMappingData().soundId(sound) == -1) {
+            // Write as direct value
+            final CompoundTag directSoundValue = new CompoundTag();
+            directSoundValue.putString("sound_id", sound);
+            tag.put(key, directSoundValue);
+        }
+    }
+
     private void replaceNullValues(final RegistryEntry[] entries) {
         // Find the first non-null entry and fill the array with dummy values where needed (which is easier than remapping them to different ids in a new, smaller array)
         RegistryEntry first = null;
diff --git a/common/src/main/resources/assets/viaversion/data/items-blocks-1.20.3.nbt b/common/src/main/resources/assets/viaversion/data/extra-identifiers-1.20.3.nbt
similarity index 51%
rename from common/src/main/resources/assets/viaversion/data/items-blocks-1.20.3.nbt
rename to common/src/main/resources/assets/viaversion/data/extra-identifiers-1.20.3.nbt
index 4d60cfd51..2c801d639 100644
Binary files a/common/src/main/resources/assets/viaversion/data/items-blocks-1.20.3.nbt and b/common/src/main/resources/assets/viaversion/data/extra-identifiers-1.20.3.nbt differ
diff --git a/common/src/main/resources/assets/viaversion/data/itemIds-1.20.3.nbt b/common/src/main/resources/assets/viaversion/data/itemIds-1.20.3.nbt
deleted file mode 100644
index 0f02d99b0..000000000
Binary files a/common/src/main/resources/assets/viaversion/data/itemIds-1.20.3.nbt and /dev/null differ