diff --git a/src/datapack/mod.rs b/src/datapack/mod.rs
index 74e4865..db19eea 100644
--- a/src/datapack/mod.rs
+++ b/src/datapack/mod.rs
@@ -90,14 +90,14 @@ impl Datapack {
     /// Add a function to the tick function list.
     pub fn add_tick(&mut self, function: &str) {
         self.namespace_mut("minecraft")
-            .tag_mut("tick", tag::TagType::Functions)
+            .tag_mut("tick", tag::TagType::Function)
             .add_value(tag::TagValue::Simple(function.to_string()));
     }
 
     /// Add a function to the load function list.
     pub fn add_load(&mut self, function: &str) {
         self.namespace_mut("minecraft")
-            .tag_mut("load", tag::TagType::Functions)
+            .tag_mut("load", tag::TagType::Function)
             .add_value(tag::TagValue::Simple(function.to_string()));
     }
 
@@ -111,17 +111,21 @@ impl Datapack {
     #[tracing::instrument(level = "debug", skip(self))]
     pub fn compile(&self, options: &CompileOptions) -> VFolder {
         tracing::debug!("Compiling datapack: {:?}", self);
+        let options = CompileOptions {
+            pack_format: self.pack_format,
+            ..options.clone()
+        };
 
         let compiler_state = Mutex::new(CompilerState::default());
 
         let mut root_folder = self.custom_files.clone();
-        let mcmeta = generate_mcmeta(self, options, &compiler_state);
+        let mcmeta = generate_mcmeta(self, &options, &compiler_state);
         root_folder.add_file("pack.mcmeta", mcmeta);
         let mut data_folder = VFolder::new();
 
         // Compile namespaces
         for (name, namespace) in &self.namespaces {
-            let namespace_folder = namespace.compile(options, &compiler_state);
+            let namespace_folder = namespace.compile(&options, &compiler_state);
             data_folder.add_existing_folder(name, namespace_folder);
         }
 
diff --git a/src/datapack/namespace.rs b/src/datapack/namespace.rs
index f1f2ab9..99f53c3 100644
--- a/src/datapack/namespace.rs
+++ b/src/datapack/namespace.rs
@@ -3,7 +3,7 @@
 use crate::{
     util::{
         compile::{CompileOptions, FunctionCompilerState, MutCompilerState},
-        ExtendableQueue,
+        pack_format, ExtendableQueue,
     },
     virtual_fs::VFolder,
 };
@@ -101,7 +101,10 @@ impl Namespace {
         while let Some((path, function)) = functions.next() {
             let function_state = FunctionCompilerState::new(&path, &self.name, functions.clone());
             root_folder.add_file(
-                &format!("function/{path}.mcfunction"),
+                &format!(
+                    "{directory_name}/{path}.mcfunction",
+                    directory_name = pack_format::function_directory_name(options.pack_format)
+                ),
                 function.compile(options, state, &function_state),
             );
         }
@@ -109,7 +112,13 @@ impl Namespace {
         // compile tags
         for ((path, tag_type), tag) in &self.tags {
             let vfile = tag.compile(options, state);
-            root_folder.add_file(&format!("tags/{tag_type}/{path}.json"), vfile);
+            root_folder.add_file(
+                &format!(
+                    "tags/{tag_directory}/{path}.json",
+                    tag_directory = tag_type.get_directory_name(options.pack_format)
+                ),
+                vfile,
+            );
         }
 
         root_folder
diff --git a/src/datapack/tag.rs b/src/datapack/tag.rs
index 7aebde5..ee95cdd 100644
--- a/src/datapack/tag.rs
+++ b/src/datapack/tag.rs
@@ -68,31 +68,65 @@ impl Tag {
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub enum TagType {
     /// A tag for blocks.
-    Blocks,
+    Block,
     /// A tag for fluids.
-    Fluids,
+    Fluid,
     /// A tag for items.
-    Items,
+    Item,
     /// A tag for entities.
-    Entities,
+    Entity,
     /// A tag for game events.
-    GameEvents,
+    GameEvent,
     /// A tag for functions.
-    Functions,
-    /// A custom tag
-    /// `Others(<registry path>)` => `data/<namespace>/tags/<registry path>`
-    Others(String),
+    Function,
+    /// A custom tag type.
+    /// `Other(<registry path>)` => `data/<namespace>/tags/<registry path>`
+    Other(String),
 }
+
+impl TagType {
+    #[must_use]
+    pub fn get_directory_name(&self, pack_format: u8) -> &str {
+        if pack_format < 43 {
+            match self {
+                Self::Block => "blocks",
+                Self::Fluid => "fluids",
+                Self::Item => "items",
+                Self::Entity => "entity_types",
+                Self::GameEvent => "game_events",
+                Self::Function => "functions",
+                Self::Other(path) => path,
+            }
+        } else {
+            match self {
+                Self::Block => "block",
+                Self::Fluid => "fluid",
+                Self::Item => "item",
+                Self::Entity => "entity_type",
+                Self::GameEvent => "game_event",
+                Self::Function => {
+                    if pack_format < 45 {
+                        "functions"
+                    } else {
+                        "function"
+                    }
+                }
+                Self::Other(path) => path,
+            }
+        }
+    }
+}
+
 impl Display for TagType {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         let str = match self {
-            Self::Blocks => "block".to_string(),
-            Self::Fluids => "fluid".to_string(),
-            Self::Items => "item".to_string(),
-            Self::Entities => "entity_type".to_string(),
-            Self::GameEvents => "game_event".to_string(),
-            Self::Functions => "function".to_string(),
-            Self::Others(path) => path.to_string(),
+            Self::Block => "block".to_string(),
+            Self::Fluid => "fluid".to_string(),
+            Self::Item => "item".to_string(),
+            Self::Entity => "entity_type".to_string(),
+            Self::GameEvent => "game_event".to_string(),
+            Self::Function => "function".to_string(),
+            Self::Other(path) => path.to_string(),
         };
         f.write_str(&str)
     }
diff --git a/src/util/compile.rs b/src/util/compile.rs
index 4c52632..cc6927a 100644
--- a/src/util/compile.rs
+++ b/src/util/compile.rs
@@ -4,7 +4,7 @@ use std::sync::Mutex;
 
 use getset::Getters;
 
-use crate::datapack::Function;
+use crate::datapack::{Datapack, Function};
 
 use super::extendable_queue::ExtendableQueue;
 
@@ -13,6 +13,8 @@ use super::extendable_queue::ExtendableQueue;
 #[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 #[derive(Debug, Clone)]
 pub struct CompileOptions {
+    /// The pack format of the target datapack.
+    pub(crate) pack_format: u8,
     /// Whether to compile in debug mode.
     pub(crate) debug: bool,
 }
@@ -21,13 +23,16 @@ impl CompileOptions {
     /// Set whether to compile in debug mode.
     #[must_use]
     pub fn with_debug(self, debug: bool) -> Self {
-        Self { debug }
+        Self { debug, ..self }
     }
 }
 
 impl Default for CompileOptions {
     fn default() -> Self {
-        Self { debug: true }
+        Self {
+            pack_format: Datapack::LATEST_FORMAT,
+            debug: true,
+        }
     }
 }
 
diff --git a/src/util/mod.rs b/src/util/mod.rs
index 78121e0..f8757c7 100644
--- a/src/util/mod.rs
+++ b/src/util/mod.rs
@@ -2,6 +2,7 @@
 
 pub mod compile;
 mod extendable_queue;
+pub(crate) mod pack_format;
 
 #[doc(inline)]
 pub use extendable_queue::ExtendableQueue;
diff --git a/src/util/pack_format.rs b/src/util/pack_format.rs
new file mode 100644
index 0000000..43321c5
--- /dev/null
+++ b/src/util/pack_format.rs
@@ -0,0 +1,9 @@
+/// Get the name of the function directory depending on the pack format.
+#[must_use]
+pub const fn function_directory_name(pack_format: u8) -> &'static str {
+    if pack_format < 45 {
+        "functions"
+    } else {
+        "function"
+    }
+}